AEROIYNiIMIC JAlII INVE ST IGAHONS U HAL DEDOLT PART ONE report investigated wing design parameters part two will study horizontal tails winglets force arrangements HORIZONTAL TAILS thin undercambered Davis wing airfoil required marked increase tail lift create proper lift proportion stable flight door opened investigation horizontal tails Lift can adjusted using three factors Area airfoil angle attack standard stabilizers area 25% wing area has 6% flat-bottom airfoil proved usable wings other chatges investigated However investigation factors seemed worthwhile program nature initiated using problem thin Davis airfoil wing increase rate climb appreciated attempts aileviate glide problem proved fruitless Adjustments force arrangement made until optimum performance dead air conditions point appeared use thin undercambered airfoil both wing stab provided efficient flight average flight Satisfactory flights first obtained wing simply increasing angle attack standard stabilizer 20 effectively created proper proportion between wing tail lift next try involved similar stabilizer airfoil increased 8% thickness As expected change angle attacldiad reduced obtain satisfactory flight proved just another way adjust lift proportion comparative flying indicated no change performance point larger stab produced using 8% airfoil area increase 30% Adjusting lift proportion required further reduction angle attack Actuaily returned setting created original problem the _______ 6%-thick 25%-area stab conclusion needed lift could be created airfoil angle attack increasing area Flights 30% stab positive rate climb reduced bit glide slower reduc tion sink rate would indicate plus factor dead air flying Another investigation attempt use additional lift generated thin undercambered Davis airfoil Could gain achieved trading increased airfoil lift decrease area Another stabilizer built using 7% Davis #5 airfoil 20% area created lift angle attack required satisfactory flight much less others 28 Model Aviation Muiholland launches another comparative flight Valkyrle Field Manatee County Florida 112 CHORD 0 0 0 uJ ITIP CHORD 20WINGLET LINE OF FLIGHT WINGTIP MOUNT VERTICAL TO LINE OF FLIGHT NOT TO DIH ANGLE DIagram 3 \mRusT GRAVITY NEUTRAL STABILITY WING Cit--TAIL LIFT MEANCIL~ times higher catch came desired thermal conditions brought combination flown within boundaries thermal flight normal However thermal small best could fly through time model would enter thermal abrupt stall would result would continue through several oscillations before settling down again Natiirally altitude lost process conclusion came wing encountered thermal effect before tail did tail force strong enough control disruptionsomething seen other arrangements anyone has other ideas would appreciated final horizontal tail investigation involved stab 18% area 8% flat-bottom airfoil interchanged standard tail no flight difference seen conclusion lift both stabilizers similar smaller tail produced lift match larger because its thicker airfoil final thought larger tail could have advantage low speeds airfoil lift affected speed area Conclusion appears juggling three lift factors tails reasonable concept can produce similar performance Considering flight parameters did appear standard stabilizer configuration 6% airfoil 25% stab area did desired work very effectively others offered distinct advantage WINGLETS casual observer could impressed Witcombs NASA experiments winglets Burt Rutans application Witcombs findings also impressive Lately see winglets various commercial jets including 747s Hey guys found something good small effort required investigate seemed worthwhile date have taken KISS-style Keep Simple Stupid look results say look again some good Most us can point some past experience tip plates sort another have very few instances good can claimed So important thought winglets familiar tip plates Instead complex create actions forces Since investigative report will dig winglet theory simple description actions should First basic wing efficiency suffers because lift lost drag increased because hiher pressure wings lower surface likes travel around wingtip lower pressure top side Tip plates simple attempt alleviate negative factor usually failed because added excessive drag winglet theory supposed superior through use basic aerodynamics creation new positive force negative tip factors can reduced using minimum tip chord high aspect ratio However used necessary extreme factors lead other negative factors can negate gain Witcomb found winglets could effectively increase aspect ratio actually doing winglets become part wing span winglets tip chord less actual wingtip tips effect less narrow plus less pressure movement drag Additional help also provided fact winglets really act like wings gain positive force winglets have definite airfoil has angle attack line flight angle set winglets lift force aimed forward models propeller example object add winglets lift force aircrafts propulsion force offset additional drag created winglet itself Witcomb felt total winglet effects produced positive factor thus useful Rutans findings September 1993 29 TAIL UFT WINGCIL 2I MEAN CII \ ThRUSTI\utu OF FLIGHT GRAVITY DIagram 4 inboard view wingiet shows its airfoil shape set produce lift slightly forward trajectory offset drag Sheet balsa winglets added Schuemann wing evaluation comparison tip plates #101 Extra Hands below Makes covering easy jiIu #401 Digger left Easiest use hinging tool available $335 ELDON J LIND COMPANY 3151 Caravelle Dr Lake Havasu City AZ 86403 602 453-7970 Send self-addressed stamped envelope tar catalog products M/C & Visa aceptad apparent proof Specific parameters must followed assure success complicated have often led astray some wonder full-scale world after much effort has proven little use models Experience has taught us try things simple way possible go mind usable wing canard knew what its performance tip plates usable normal-configuration design Using Witcomb parameters made some winglets replace wings tip plates first flights made normal-configuration test plane models normal tendency search during steep climb flown up ladder winglets flight path held true no pilot help needed short say like glide mode tended hold straight course directional control remained positive sink rate may have lower nothing significant greatest surprise came canard searching tendencies similar normal configuration As seen before search tendency now eliminated glide mode canard would occasionally rock bit like boat traveling wave trough Dutch roll familiar cause cure remalned mysterious Amazingly winglets action gone flight became rock solid Remember common tip plates Conclusion Winglets have some obvious merits further development may some gold hills will provide basic winglet parameters Note KISS approach used simple flat-bottom airfoil seems possible semisymmetrical section might reduce drag bit knows what development might bring FORCE ARRANGEMENTS Force arrangements depict longitudinal forces will work given design Such arrangement can adjusted create various sorts flight Examples such adjustments center gravity CG location wing lift tail lift mean lift point thrust should understood various forces intertwined change may very well affect another best part can produce arrangement will create sort flight wish just remember what may great goose may suit gander first investigated aerodynam ically arrange design would longitudinally stable over very wide speed range instance powered gliders have power-on speed considerably greater glide speed Lift increases square speed increase fundamental problem becomes control increased wing lift under power much less lift gliding Fortunately aerodynamic factor can used effectively solve problem lift airfoils increases propor tionally speed becomes possible use airfoil control another control airfoils lift will increase proportion main airfoil Tail lift can used control wing lift over wide speed range investigated suitable lift proportion between wing tail determined results better other method might used comparison made basic design glide power modes established given power level additional power added no other changes considerable downthrust required achieve satisfactory climb angle models performance excellent idea speed increase would create problem frowned upon better way investigated similar design making changes force arrangement tail lift increased moved mean coefficient lift C1 aft amount tail lift gradually increased until model tended fly level under power launched level After launch elevator used establish desirable climb angle elevator neutralized flight would continue established angle obvious power under complete control As might expected glide mode suffered up trim used obtain proper glide angle answer proved CG changewhich should have obvious beginning stability CG must forward mean C1 moved mean C1 aft control power created longer gravity-force lever model now effectively nose heavy CG moved aft relate properly mean lift location glide angle became desirable interesting see CG move did affect power mode just aerodynamics would indicate discussed airfoil investigations part briefly referred force arrangement proved method would control additional lift created undercambered airfoil amount tail lift required instance far greater other time mean C1 moved further aft yet CG brought compliance both power glide modes excellent Conclusion Downthrust can used control power wide speed range downthrust angle set satisfactorily given speed increase speed will require greater angle will detract power-on efficiency aerodynamic power control investigated provides power control over reasonable speed range normally adding power speed will affect Continued page 58 30 Model Aviation SERIOUS MODEL BUILDERS easy ccurate straIght iviinoui access #500A- $10885 access #50DB $191 AO #2HZ Duplicator Contour Sander Turn out beautiful edges Simple easy Standard $2055 xe- $5955 FOX ER OF THE PACK proud owner finest American made model airplane motor available Fox offers RIG control line model airplane motors following sizes 15BB 25 Bushing 25BB 35 Stunt GIL 40 Sport 4OBB 4OBB ABC 45BB Ring 5OBB Ring Quickee 500 6OBB Ring 6OBB ABC 6OBB ABC Pipe 74BB Ring 74BB ABC Fox motors rugged durable provide plenty power leader pack Fly Fox FOX MANUFACTURING COMPANY 5305 Towson Avenue Smith AR 72901 646-1656 501 646-1757 MATERIALS SOURCES have local hobby dealer try buy items him possible no dealer available near cant wont supply needs try following specialty houses sell direct modeler Sig Manufacturing Co 401-7 S Front St Montezuma IA 50171 Tel 515 623-5154 Balsa covering materials CL accessories Smiths Metal Fuel Tanks 521 Jansen Ave San Dimas CA 91773 Tel 714 592-2100 Standard custom-made fuel tanks RIL Industries 1831 Business Center Dr Duarte CA 91010 Tel818 359-0016 Engines lead putty after-run oils Vinylwrite Custom Lettering 16043 Tulsa St Granada Hills CA 91344 Tel NEW $3000 Power Source 6 volt 1200 miliamp GEL CELL Receiver Battery 818 363-7131 Standard custom vinyl lettering Fox Manufacturing Co 5305 Towson Ave Fort Smith AR 72901 Tel 501 646-1656 Engines bellcranks spinners miscellaneous components Hobby Lobby Tel 615 373-1444 Tower Hobbies Tel 800 637-6050 Engines covering materials various usable accessories dynamicldeBolt Continued page 30 neutral stabilitythe flight path will whatever direction plane pointed Obviously makes suitable RC aircraft arrangement also adds efficiency beyond gain lack downthrust additional tail lift required models total lift increased NEW $2500 MAT ESV Vultmutmu Instant Voltage reading under 300 miliamp load Llights indicate battery condition No Guessing Reads transmiter voltage well 48 Nicad battery voltage Nicad users can compare 48 Nicad GELL CELL Once compare youll know choice champions investigations made electric-powered Enduro-style RC models factors would also apply other model types especially true neutral-stability force arrangement actually drew previous Pattern design experience Pattern effective speed control must evaluators always say good Pattern design line flight pilot points short findings applicable model designs What have reported represents two years judicious investigations hope findings have proven interesting may some value Further hope work may inspire own investigations Better flying can through aerodynamics $4900 MAT AC/DC Chargur Perfect charging rate 400 miliamps goes automatic trickle charged LEDs show battery fully charged CANNOT overcharge Use 12 volt battery field car battery provided lighter socket plug Mona Avuin TECHNOVICY 12848 Touchslone Place Palm Beach Gardens FL 33418 Telephone 407 626-6955 FAX 407 626-1588 58 Model Aviation charger designed specifically ou highly successful battery voltmeter check exact condition battery
Edition: Model Aviation - 1993/09
Page Numbers: 28, 29, 30, 58
AEROIYNiIMIC JAlII INVE ST IGAHONS U HAL DEDOLT PART ONE report investigated wing design parameters part two will study horizontal tails winglets force arrangements HORIZONTAL TAILS thin undercambered Davis wing airfoil required marked increase tail lift create proper lift proportion stable flight door opened investigation horizontal tails Lift can adjusted using three factors Area airfoil angle attack standard stabilizers area 25% wing area has 6% flat-bottom airfoil proved usable wings other chatges investigated However investigation factors seemed worthwhile program nature initiated using problem thin Davis airfoil wing increase rate climb appreciated attempts aileviate glide problem proved fruitless Adjustments force arrangement made until optimum performance dead air conditions point appeared use thin undercambered airfoil both wing stab provided efficient flight average flight Satisfactory flights first obtained wing simply increasing angle attack standard stabilizer 20 effectively created proper proportion between wing tail lift next try involved similar stabilizer airfoil increased 8% thickness As expected change angle attacldiad reduced obtain satisfactory flight proved just another way adjust lift proportion comparative flying indicated no change performance point larger stab produced using 8% airfoil area increase 30% Adjusting lift proportion required further reduction angle attack Actuaily returned setting created original problem the _______ 6%-thick 25%-area stab conclusion needed lift could be created airfoil angle attack increasing area Flights 30% stab positive rate climb reduced bit glide slower reduc tion sink rate would indicate plus factor dead air flying Another investigation attempt use additional lift generated thin undercambered Davis airfoil Could gain achieved trading increased airfoil lift decrease area Another stabilizer built using 7% Davis #5 airfoil 20% area created lift angle attack required satisfactory flight much less others 28 Model Aviation Muiholland launches another comparative flight Valkyrle Field Manatee County Florida 112 CHORD 0 0 0 uJ ITIP CHORD 20WINGLET LINE OF FLIGHT WINGTIP MOUNT VERTICAL TO LINE OF FLIGHT NOT TO DIH ANGLE DIagram 3 \mRusT GRAVITY NEUTRAL STABILITY WING Cit--TAIL LIFT MEANCIL~ times higher catch came desired thermal conditions brought combination flown within boundaries thermal flight normal However thermal small best could fly through time model would enter thermal abrupt stall would result would continue through several oscillations before settling down again Natiirally altitude lost process conclusion came wing encountered thermal effect before tail did tail force strong enough control disruptionsomething seen other arrangements anyone has other ideas would appreciated final horizontal tail investigation involved stab 18% area 8% flat-bottom airfoil interchanged standard tail no flight difference seen conclusion lift both stabilizers similar smaller tail produced lift match larger because its thicker airfoil final thought larger tail could have advantage low speeds airfoil lift affected speed area Conclusion appears juggling three lift factors tails reasonable concept can produce similar performance Considering flight parameters did appear standard stabilizer configuration 6% airfoil 25% stab area did desired work very effectively others offered distinct advantage WINGLETS casual observer could impressed Witcombs NASA experiments winglets Burt Rutans application Witcombs findings also impressive Lately see winglets various commercial jets including 747s Hey guys found something good small effort required investigate seemed worthwhile date have taken KISS-style Keep Simple Stupid look results say look again some good Most us can point some past experience tip plates sort another have very few instances good can claimed So important thought winglets familiar tip plates Instead complex create actions forces Since investigative report will dig winglet theory simple description actions should First basic wing efficiency suffers because lift lost drag increased because hiher pressure wings lower surface likes travel around wingtip lower pressure top side Tip plates simple attempt alleviate negative factor usually failed because added excessive drag winglet theory supposed superior through use basic aerodynamics creation new positive force negative tip factors can reduced using minimum tip chord high aspect ratio However used necessary extreme factors lead other negative factors can negate gain Witcomb found winglets could effectively increase aspect ratio actually doing winglets become part wing span winglets tip chord less actual wingtip tips effect less narrow plus less pressure movement drag Additional help also provided fact winglets really act like wings gain positive force winglets have definite airfoil has angle attack line flight angle set winglets lift force aimed forward models propeller example object add winglets lift force aircrafts propulsion force offset additional drag created winglet itself Witcomb felt total winglet effects produced positive factor thus useful Rutans findings September 1993 29 TAIL UFT WINGCIL 2I MEAN CII \ ThRUSTI\utu OF FLIGHT GRAVITY DIagram 4 inboard view wingiet shows its airfoil shape set produce lift slightly forward trajectory offset drag Sheet balsa winglets added Schuemann wing evaluation comparison tip plates #101 Extra Hands below Makes covering easy jiIu #401 Digger left Easiest use hinging tool available $335 ELDON J LIND COMPANY 3151 Caravelle Dr Lake Havasu City AZ 86403 602 453-7970 Send self-addressed stamped envelope tar catalog products M/C & Visa aceptad apparent proof Specific parameters must followed assure success complicated have often led astray some wonder full-scale world after much effort has proven little use models Experience has taught us try things simple way possible go mind usable wing canard knew what its performance tip plates usable normal-configuration design Using Witcomb parameters made some winglets replace wings tip plates first flights made normal-configuration test plane models normal tendency search during steep climb flown up ladder winglets flight path held true no pilot help needed short say like glide mode tended hold straight course directional control remained positive sink rate may have lower nothing significant greatest surprise came canard searching tendencies similar normal configuration As seen before search tendency now eliminated glide mode canard would occasionally rock bit like boat traveling wave trough Dutch roll familiar cause cure remalned mysterious Amazingly winglets action gone flight became rock solid Remember common tip plates Conclusion Winglets have some obvious merits further development may some gold hills will provide basic winglet parameters Note KISS approach used simple flat-bottom airfoil seems possible semisymmetrical section might reduce drag bit knows what development might bring FORCE ARRANGEMENTS Force arrangements depict longitudinal forces will work given design Such arrangement can adjusted create various sorts flight Examples such adjustments center gravity CG location wing lift tail lift mean lift point thrust should understood various forces intertwined change may very well affect another best part can produce arrangement will create sort flight wish just remember what may great goose may suit gander first investigated aerodynam ically arrange design would longitudinally stable over very wide speed range instance powered gliders have power-on speed considerably greater glide speed Lift increases square speed increase fundamental problem becomes control increased wing lift under power much less lift gliding Fortunately aerodynamic factor can used effectively solve problem lift airfoils increases propor tionally speed becomes possible use airfoil control another control airfoils lift will increase proportion main airfoil Tail lift can used control wing lift over wide speed range investigated suitable lift proportion between wing tail determined results better other method might used comparison made basic design glide power modes established given power level additional power added no other changes considerable downthrust required achieve satisfactory climb angle models performance excellent idea speed increase would create problem frowned upon better way investigated similar design making changes force arrangement tail lift increased moved mean coefficient lift C1 aft amount tail lift gradually increased until model tended fly level under power launched level After launch elevator used establish desirable climb angle elevator neutralized flight would continue established angle obvious power under complete control As might expected glide mode suffered up trim used obtain proper glide angle answer proved CG changewhich should have obvious beginning stability CG must forward mean C1 moved mean C1 aft control power created longer gravity-force lever model now effectively nose heavy CG moved aft relate properly mean lift location glide angle became desirable interesting see CG move did affect power mode just aerodynamics would indicate discussed airfoil investigations part briefly referred force arrangement proved method would control additional lift created undercambered airfoil amount tail lift required instance far greater other time mean C1 moved further aft yet CG brought compliance both power glide modes excellent Conclusion Downthrust can used control power wide speed range downthrust angle set satisfactorily given speed increase speed will require greater angle will detract power-on efficiency aerodynamic power control investigated provides power control over reasonable speed range normally adding power speed will affect Continued page 58 30 Model Aviation SERIOUS MODEL BUILDERS easy ccurate straIght iviinoui access #500A- $10885 access #50DB $191 AO #2HZ Duplicator Contour Sander Turn out beautiful edges Simple easy Standard $2055 xe- $5955 FOX ER OF THE PACK proud owner finest American made model airplane motor available Fox offers RIG control line model airplane motors following sizes 15BB 25 Bushing 25BB 35 Stunt GIL 40 Sport 4OBB 4OBB ABC 45BB Ring 5OBB Ring Quickee 500 6OBB Ring 6OBB ABC 6OBB ABC Pipe 74BB Ring 74BB ABC Fox motors rugged durable provide plenty power leader pack Fly Fox FOX MANUFACTURING COMPANY 5305 Towson Avenue Smith AR 72901 646-1656 501 646-1757 MATERIALS SOURCES have local hobby dealer try buy items him possible no dealer available near cant wont supply needs try following specialty houses sell direct modeler Sig Manufacturing Co 401-7 S Front St Montezuma IA 50171 Tel 515 623-5154 Balsa covering materials CL accessories Smiths Metal Fuel Tanks 521 Jansen Ave San Dimas CA 91773 Tel 714 592-2100 Standard custom-made fuel tanks RIL Industries 1831 Business Center Dr Duarte CA 91010 Tel818 359-0016 Engines lead putty after-run oils Vinylwrite Custom Lettering 16043 Tulsa St Granada Hills CA 91344 Tel NEW $3000 Power Source 6 volt 1200 miliamp GEL CELL Receiver Battery 818 363-7131 Standard custom vinyl lettering Fox Manufacturing Co 5305 Towson Ave Fort Smith AR 72901 Tel 501 646-1656 Engines bellcranks spinners miscellaneous components Hobby Lobby Tel 615 373-1444 Tower Hobbies Tel 800 637-6050 Engines covering materials various usable accessories dynamicldeBolt Continued page 30 neutral stabilitythe flight path will whatever direction plane pointed Obviously makes suitable RC aircraft arrangement also adds efficiency beyond gain lack downthrust additional tail lift required models total lift increased NEW $2500 MAT ESV Vultmutmu Instant Voltage reading under 300 miliamp load Llights indicate battery condition No Guessing Reads transmiter voltage well 48 Nicad battery voltage Nicad users can compare 48 Nicad GELL CELL Once compare youll know choice champions investigations made electric-powered Enduro-style RC models factors would also apply other model types especially true neutral-stability force arrangement actually drew previous Pattern design experience Pattern effective speed control must evaluators always say good Pattern design line flight pilot points short findings applicable model designs What have reported represents two years judicious investigations hope findings have proven interesting may some value Further hope work may inspire own investigations Better flying can through aerodynamics $4900 MAT AC/DC Chargur Perfect charging rate 400 miliamps goes automatic trickle charged LEDs show battery fully charged CANNOT overcharge Use 12 volt battery field car battery provided lighter socket plug Mona Avuin TECHNOVICY 12848 Touchslone Place Palm Beach Gardens FL 33418 Telephone 407 626-6955 FAX 407 626-1588 58 Model Aviation charger designed specifically ou highly successful battery voltmeter check exact condition battery
Edition: Model Aviation - 1993/09
Page Numbers: 28, 29, 30, 58
AEROIYNiIMIC JAlII INVE ST IGAHONS U HAL DEDOLT PART ONE report investigated wing design parameters part two will study horizontal tails winglets force arrangements HORIZONTAL TAILS thin undercambered Davis wing airfoil required marked increase tail lift create proper lift proportion stable flight door opened investigation horizontal tails Lift can adjusted using three factors Area airfoil angle attack standard stabilizers area 25% wing area has 6% flat-bottom airfoil proved usable wings other chatges investigated However investigation factors seemed worthwhile program nature initiated using problem thin Davis airfoil wing increase rate climb appreciated attempts aileviate glide problem proved fruitless Adjustments force arrangement made until optimum performance dead air conditions point appeared use thin undercambered airfoil both wing stab provided efficient flight average flight Satisfactory flights first obtained wing simply increasing angle attack standard stabilizer 20 effectively created proper proportion between wing tail lift next try involved similar stabilizer airfoil increased 8% thickness As expected change angle attacldiad reduced obtain satisfactory flight proved just another way adjust lift proportion comparative flying indicated no change performance point larger stab produced using 8% airfoil area increase 30% Adjusting lift proportion required further reduction angle attack Actuaily returned setting created original problem the _______ 6%-thick 25%-area stab conclusion needed lift could be created airfoil angle attack increasing area Flights 30% stab positive rate climb reduced bit glide slower reduc tion sink rate would indicate plus factor dead air flying Another investigation attempt use additional lift generated thin undercambered Davis airfoil Could gain achieved trading increased airfoil lift decrease area Another stabilizer built using 7% Davis #5 airfoil 20% area created lift angle attack required satisfactory flight much less others 28 Model Aviation Muiholland launches another comparative flight Valkyrle Field Manatee County Florida 112 CHORD 0 0 0 uJ ITIP CHORD 20WINGLET LINE OF FLIGHT WINGTIP MOUNT VERTICAL TO LINE OF FLIGHT NOT TO DIH ANGLE DIagram 3 \mRusT GRAVITY NEUTRAL STABILITY WING Cit--TAIL LIFT MEANCIL~ times higher catch came desired thermal conditions brought combination flown within boundaries thermal flight normal However thermal small best could fly through time model would enter thermal abrupt stall would result would continue through several oscillations before settling down again Natiirally altitude lost process conclusion came wing encountered thermal effect before tail did tail force strong enough control disruptionsomething seen other arrangements anyone has other ideas would appreciated final horizontal tail investigation involved stab 18% area 8% flat-bottom airfoil interchanged standard tail no flight difference seen conclusion lift both stabilizers similar smaller tail produced lift match larger because its thicker airfoil final thought larger tail could have advantage low speeds airfoil lift affected speed area Conclusion appears juggling three lift factors tails reasonable concept can produce similar performance Considering flight parameters did appear standard stabilizer configuration 6% airfoil 25% stab area did desired work very effectively others offered distinct advantage WINGLETS casual observer could impressed Witcombs NASA experiments winglets Burt Rutans application Witcombs findings also impressive Lately see winglets various commercial jets including 747s Hey guys found something good small effort required investigate seemed worthwhile date have taken KISS-style Keep Simple Stupid look results say look again some good Most us can point some past experience tip plates sort another have very few instances good can claimed So important thought winglets familiar tip plates Instead complex create actions forces Since investigative report will dig winglet theory simple description actions should First basic wing efficiency suffers because lift lost drag increased because hiher pressure wings lower surface likes travel around wingtip lower pressure top side Tip plates simple attempt alleviate negative factor usually failed because added excessive drag winglet theory supposed superior through use basic aerodynamics creation new positive force negative tip factors can reduced using minimum tip chord high aspect ratio However used necessary extreme factors lead other negative factors can negate gain Witcomb found winglets could effectively increase aspect ratio actually doing winglets become part wing span winglets tip chord less actual wingtip tips effect less narrow plus less pressure movement drag Additional help also provided fact winglets really act like wings gain positive force winglets have definite airfoil has angle attack line flight angle set winglets lift force aimed forward models propeller example object add winglets lift force aircrafts propulsion force offset additional drag created winglet itself Witcomb felt total winglet effects produced positive factor thus useful Rutans findings September 1993 29 TAIL UFT WINGCIL 2I MEAN CII \ ThRUSTI\utu OF FLIGHT GRAVITY DIagram 4 inboard view wingiet shows its airfoil shape set produce lift slightly forward trajectory offset drag Sheet balsa winglets added Schuemann wing evaluation comparison tip plates #101 Extra Hands below Makes covering easy jiIu #401 Digger left Easiest use hinging tool available $335 ELDON J LIND COMPANY 3151 Caravelle Dr Lake Havasu City AZ 86403 602 453-7970 Send self-addressed stamped envelope tar catalog products M/C & Visa aceptad apparent proof Specific parameters must followed assure success complicated have often led astray some wonder full-scale world after much effort has proven little use models Experience has taught us try things simple way possible go mind usable wing canard knew what its performance tip plates usable normal-configuration design Using Witcomb parameters made some winglets replace wings tip plates first flights made normal-configuration test plane models normal tendency search during steep climb flown up ladder winglets flight path held true no pilot help needed short say like glide mode tended hold straight course directional control remained positive sink rate may have lower nothing significant greatest surprise came canard searching tendencies similar normal configuration As seen before search tendency now eliminated glide mode canard would occasionally rock bit like boat traveling wave trough Dutch roll familiar cause cure remalned mysterious Amazingly winglets action gone flight became rock solid Remember common tip plates Conclusion Winglets have some obvious merits further development may some gold hills will provide basic winglet parameters Note KISS approach used simple flat-bottom airfoil seems possible semisymmetrical section might reduce drag bit knows what development might bring FORCE ARRANGEMENTS Force arrangements depict longitudinal forces will work given design Such arrangement can adjusted create various sorts flight Examples such adjustments center gravity CG location wing lift tail lift mean lift point thrust should understood various forces intertwined change may very well affect another best part can produce arrangement will create sort flight wish just remember what may great goose may suit gander first investigated aerodynam ically arrange design would longitudinally stable over very wide speed range instance powered gliders have power-on speed considerably greater glide speed Lift increases square speed increase fundamental problem becomes control increased wing lift under power much less lift gliding Fortunately aerodynamic factor can used effectively solve problem lift airfoils increases propor tionally speed becomes possible use airfoil control another control airfoils lift will increase proportion main airfoil Tail lift can used control wing lift over wide speed range investigated suitable lift proportion between wing tail determined results better other method might used comparison made basic design glide power modes established given power level additional power added no other changes considerable downthrust required achieve satisfactory climb angle models performance excellent idea speed increase would create problem frowned upon better way investigated similar design making changes force arrangement tail lift increased moved mean coefficient lift C1 aft amount tail lift gradually increased until model tended fly level under power launched level After launch elevator used establish desirable climb angle elevator neutralized flight would continue established angle obvious power under complete control As might expected glide mode suffered up trim used obtain proper glide angle answer proved CG changewhich should have obvious beginning stability CG must forward mean C1 moved mean C1 aft control power created longer gravity-force lever model now effectively nose heavy CG moved aft relate properly mean lift location glide angle became desirable interesting see CG move did affect power mode just aerodynamics would indicate discussed airfoil investigations part briefly referred force arrangement proved method would control additional lift created undercambered airfoil amount tail lift required instance far greater other time mean C1 moved further aft yet CG brought compliance both power glide modes excellent Conclusion Downthrust can used control power wide speed range downthrust angle set satisfactorily given speed increase speed will require greater angle will detract power-on efficiency aerodynamic power control investigated provides power control over reasonable speed range normally adding power speed will affect Continued page 58 30 Model Aviation SERIOUS MODEL BUILDERS easy ccurate straIght iviinoui access #500A- $10885 access #50DB $191 AO #2HZ Duplicator Contour Sander Turn out beautiful edges Simple easy Standard $2055 xe- $5955 FOX ER OF THE PACK proud owner finest American made model airplane motor available Fox offers RIG control line model airplane motors following sizes 15BB 25 Bushing 25BB 35 Stunt GIL 40 Sport 4OBB 4OBB ABC 45BB Ring 5OBB Ring Quickee 500 6OBB Ring 6OBB ABC 6OBB ABC Pipe 74BB Ring 74BB ABC Fox motors rugged durable provide plenty power leader pack Fly Fox FOX MANUFACTURING COMPANY 5305 Towson Avenue Smith AR 72901 646-1656 501 646-1757 MATERIALS SOURCES have local hobby dealer try buy items him possible no dealer available near cant wont supply needs try following specialty houses sell direct modeler Sig Manufacturing Co 401-7 S Front St Montezuma IA 50171 Tel 515 623-5154 Balsa covering materials CL accessories Smiths Metal Fuel Tanks 521 Jansen Ave San Dimas CA 91773 Tel 714 592-2100 Standard custom-made fuel tanks RIL Industries 1831 Business Center Dr Duarte CA 91010 Tel818 359-0016 Engines lead putty after-run oils Vinylwrite Custom Lettering 16043 Tulsa St Granada Hills CA 91344 Tel NEW $3000 Power Source 6 volt 1200 miliamp GEL CELL Receiver Battery 818 363-7131 Standard custom vinyl lettering Fox Manufacturing Co 5305 Towson Ave Fort Smith AR 72901 Tel 501 646-1656 Engines bellcranks spinners miscellaneous components Hobby Lobby Tel 615 373-1444 Tower Hobbies Tel 800 637-6050 Engines covering materials various usable accessories dynamicldeBolt Continued page 30 neutral stabilitythe flight path will whatever direction plane pointed Obviously makes suitable RC aircraft arrangement also adds efficiency beyond gain lack downthrust additional tail lift required models total lift increased NEW $2500 MAT ESV Vultmutmu Instant Voltage reading under 300 miliamp load Llights indicate battery condition No Guessing Reads transmiter voltage well 48 Nicad battery voltage Nicad users can compare 48 Nicad GELL CELL Once compare youll know choice champions investigations made electric-powered Enduro-style RC models factors would also apply other model types especially true neutral-stability force arrangement actually drew previous Pattern design experience Pattern effective speed control must evaluators always say good Pattern design line flight pilot points short findings applicable model designs What have reported represents two years judicious investigations hope findings have proven interesting may some value Further hope work may inspire own investigations Better flying can through aerodynamics $4900 MAT AC/DC Chargur Perfect charging rate 400 miliamps goes automatic trickle charged LEDs show battery fully charged CANNOT overcharge Use 12 volt battery field car battery provided lighter socket plug Mona Avuin TECHNOVICY 12848 Touchslone Place Palm Beach Gardens FL 33418 Telephone 407 626-6955 FAX 407 626-1588 58 Model Aviation charger designed specifically ou highly successful battery voltmeter check exact condition battery
Edition: Model Aviation - 1993/09
Page Numbers: 28, 29, 30, 58
AEROIYNiIMIC JAlII INVE ST IGAHONS U HAL DEDOLT PART ONE report investigated wing design parameters part two will study horizontal tails winglets force arrangements HORIZONTAL TAILS thin undercambered Davis wing airfoil required marked increase tail lift create proper lift proportion stable flight door opened investigation horizontal tails Lift can adjusted using three factors Area airfoil angle attack standard stabilizers area 25% wing area has 6% flat-bottom airfoil proved usable wings other chatges investigated However investigation factors seemed worthwhile program nature initiated using problem thin Davis airfoil wing increase rate climb appreciated attempts aileviate glide problem proved fruitless Adjustments force arrangement made until optimum performance dead air conditions point appeared use thin undercambered airfoil both wing stab provided efficient flight average flight Satisfactory flights first obtained wing simply increasing angle attack standard stabilizer 20 effectively created proper proportion between wing tail lift next try involved similar stabilizer airfoil increased 8% thickness As expected change angle attacldiad reduced obtain satisfactory flight proved just another way adjust lift proportion comparative flying indicated no change performance point larger stab produced using 8% airfoil area increase 30% Adjusting lift proportion required further reduction angle attack Actuaily returned setting created original problem the _______ 6%-thick 25%-area stab conclusion needed lift could be created airfoil angle attack increasing area Flights 30% stab positive rate climb reduced bit glide slower reduc tion sink rate would indicate plus factor dead air flying Another investigation attempt use additional lift generated thin undercambered Davis airfoil Could gain achieved trading increased airfoil lift decrease area Another stabilizer built using 7% Davis #5 airfoil 20% area created lift angle attack required satisfactory flight much less others 28 Model Aviation Muiholland launches another comparative flight Valkyrle Field Manatee County Florida 112 CHORD 0 0 0 uJ ITIP CHORD 20WINGLET LINE OF FLIGHT WINGTIP MOUNT VERTICAL TO LINE OF FLIGHT NOT TO DIH ANGLE DIagram 3 \mRusT GRAVITY NEUTRAL STABILITY WING Cit--TAIL LIFT MEANCIL~ times higher catch came desired thermal conditions brought combination flown within boundaries thermal flight normal However thermal small best could fly through time model would enter thermal abrupt stall would result would continue through several oscillations before settling down again Natiirally altitude lost process conclusion came wing encountered thermal effect before tail did tail force strong enough control disruptionsomething seen other arrangements anyone has other ideas would appreciated final horizontal tail investigation involved stab 18% area 8% flat-bottom airfoil interchanged standard tail no flight difference seen conclusion lift both stabilizers similar smaller tail produced lift match larger because its thicker airfoil final thought larger tail could have advantage low speeds airfoil lift affected speed area Conclusion appears juggling three lift factors tails reasonable concept can produce similar performance Considering flight parameters did appear standard stabilizer configuration 6% airfoil 25% stab area did desired work very effectively others offered distinct advantage WINGLETS casual observer could impressed Witcombs NASA experiments winglets Burt Rutans application Witcombs findings also impressive Lately see winglets various commercial jets including 747s Hey guys found something good small effort required investigate seemed worthwhile date have taken KISS-style Keep Simple Stupid look results say look again some good Most us can point some past experience tip plates sort another have very few instances good can claimed So important thought winglets familiar tip plates Instead complex create actions forces Since investigative report will dig winglet theory simple description actions should First basic wing efficiency suffers because lift lost drag increased because hiher pressure wings lower surface likes travel around wingtip lower pressure top side Tip plates simple attempt alleviate negative factor usually failed because added excessive drag winglet theory supposed superior through use basic aerodynamics creation new positive force negative tip factors can reduced using minimum tip chord high aspect ratio However used necessary extreme factors lead other negative factors can negate gain Witcomb found winglets could effectively increase aspect ratio actually doing winglets become part wing span winglets tip chord less actual wingtip tips effect less narrow plus less pressure movement drag Additional help also provided fact winglets really act like wings gain positive force winglets have definite airfoil has angle attack line flight angle set winglets lift force aimed forward models propeller example object add winglets lift force aircrafts propulsion force offset additional drag created winglet itself Witcomb felt total winglet effects produced positive factor thus useful Rutans findings September 1993 29 TAIL UFT WINGCIL 2I MEAN CII \ ThRUSTI\utu OF FLIGHT GRAVITY DIagram 4 inboard view wingiet shows its airfoil shape set produce lift slightly forward trajectory offset drag Sheet balsa winglets added Schuemann wing evaluation comparison tip plates #101 Extra Hands below Makes covering easy jiIu #401 Digger left Easiest use hinging tool available $335 ELDON J LIND COMPANY 3151 Caravelle Dr Lake Havasu City AZ 86403 602 453-7970 Send self-addressed stamped envelope tar catalog products M/C & Visa aceptad apparent proof Specific parameters must followed assure success complicated have often led astray some wonder full-scale world after much effort has proven little use models Experience has taught us try things simple way possible go mind usable wing canard knew what its performance tip plates usable normal-configuration design Using Witcomb parameters made some winglets replace wings tip plates first flights made normal-configuration test plane models normal tendency search during steep climb flown up ladder winglets flight path held true no pilot help needed short say like glide mode tended hold straight course directional control remained positive sink rate may have lower nothing significant greatest surprise came canard searching tendencies similar normal configuration As seen before search tendency now eliminated glide mode canard would occasionally rock bit like boat traveling wave trough Dutch roll familiar cause cure remalned mysterious Amazingly winglets action gone flight became rock solid Remember common tip plates Conclusion Winglets have some obvious merits further development may some gold hills will provide basic winglet parameters Note KISS approach used simple flat-bottom airfoil seems possible semisymmetrical section might reduce drag bit knows what development might bring FORCE ARRANGEMENTS Force arrangements depict longitudinal forces will work given design Such arrangement can adjusted create various sorts flight Examples such adjustments center gravity CG location wing lift tail lift mean lift point thrust should understood various forces intertwined change may very well affect another best part can produce arrangement will create sort flight wish just remember what may great goose may suit gander first investigated aerodynam ically arrange design would longitudinally stable over very wide speed range instance powered gliders have power-on speed considerably greater glide speed Lift increases square speed increase fundamental problem becomes control increased wing lift under power much less lift gliding Fortunately aerodynamic factor can used effectively solve problem lift airfoils increases propor tionally speed becomes possible use airfoil control another control airfoils lift will increase proportion main airfoil Tail lift can used control wing lift over wide speed range investigated suitable lift proportion between wing tail determined results better other method might used comparison made basic design glide power modes established given power level additional power added no other changes considerable downthrust required achieve satisfactory climb angle models performance excellent idea speed increase would create problem frowned upon better way investigated similar design making changes force arrangement tail lift increased moved mean coefficient lift C1 aft amount tail lift gradually increased until model tended fly level under power launched level After launch elevator used establish desirable climb angle elevator neutralized flight would continue established angle obvious power under complete control As might expected glide mode suffered up trim used obtain proper glide angle answer proved CG changewhich should have obvious beginning stability CG must forward mean C1 moved mean C1 aft control power created longer gravity-force lever model now effectively nose heavy CG moved aft relate properly mean lift location glide angle became desirable interesting see CG move did affect power mode just aerodynamics would indicate discussed airfoil investigations part briefly referred force arrangement proved method would control additional lift created undercambered airfoil amount tail lift required instance far greater other time mean C1 moved further aft yet CG brought compliance both power glide modes excellent Conclusion Downthrust can used control power wide speed range downthrust angle set satisfactorily given speed increase speed will require greater angle will detract power-on efficiency aerodynamic power control investigated provides power control over reasonable speed range normally adding power speed will affect Continued page 58 30 Model Aviation SERIOUS MODEL BUILDERS easy ccurate straIght iviinoui access #500A- $10885 access #50DB $191 AO #2HZ Duplicator Contour Sander Turn out 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