41 st Europea otorcraft Forum 2015 EFFECTS OF OTO CONTAMINATION ON GYOLANE FLIGHT EFOMANCE Holger uda, Falk Sachs, Jörg Seewald, Claas-Hirik ohardt L (Germa Aerospace Ceter) Liliethalplatz 7, 38108 Brauschweig, Germay Abstract This paper describes the effects of rotor cotamiatio o gyroplae flight performace such as its ifluece o propeller thrust required for cruise flight ad takeoff distace. It is kow from flight practice that rotor cotamiatio due to isects degrades the flight performace of gyroplaes sigificatly. By flight trials with a MTOsport gyroplae this degradatio has bee quatified: i order to maitai altitude at 60 kt airspeed the egie rotatioal speed has to be icreased by about 200 rpm due to the rotor cotamiatio. Cosiderig these experimetal data i the simulatio model shows that this meas a performace degradatio of about 14 %. I order to uderstad this sigificat effect a aalysis has bee coducted coectig these flight test results with the degradatio of the airfoil performace due to cotamiatio. The NACA 8-H-12 airfoil characteristics have bee determied usig XFOIL for the clea ad the cotamiated case. The drag coefficiet computed with a fixed trasitio poit ear the leadig edge (cotamiated case) is almost doubled i the relevat regio of lift coefficiets compared to the free trasitio poit calculatio (clea case). Utilizig these aerodyamic characteristics withi the overall MTOsport flight simulatio model affirms the degradatio measured i flight. Hece the computatioal results are cosidered to be valid ad the simulatio model ca be applied to ivestigate potetial flight performace improvemets of future gyroplaes. Fially a simulatio study of the takeoff performace with clea ad cotamiated rotor is preseted idicatig that the takeoff distace also icreases by more tha 16 %. 1. INTOUCTION A gyroplae is a aircraft that gets lift from a freely turig rotor ad which derives its thrust from a egie-drive propeller [1]. Historically, this type of aircraft has bee kow as autogiro or gyrocopter. It was developed by Jua de la Cierva ad i 1923 it was the first rotary-wig aircraft flyig. Early gyroplaes were powered by egies i a tractor (pullig) cofiguratio, like the Cierva C.30 from 1933 which was produced 180 times by 1945 [2]. Gyroplaes became largely eglected after sigificat improvemets i helicopters. I the ietee-fifties there was some revival of iterest i the gyroplae by Igor Bese s home-built gyroplae kits with a ope airframe ad the Fairey Compay i Great Britai. Today i Europe several maufacturers sell sigle- ad two-seater gyroplaes for the private aviatio market. This boom ca be explaied by the fasciatig flyig characteristics i combiatio with the robustess ad cost efficiecy of this kid of air vehicle. Figure 1 shows L s gyroplaes operated i Brauschweig for flight research. The MTOsport (-MTOS) has bee used i flight test programs (2010 ad 2012) for the validatio of simulatio models ad i additio to geerate flight data to study gyroplae flight dyamics. The Cavalo (-MGT) has a sigificat role i flight experimets i cooperatio with the THW (Germa Federal Agecy for Techical elief). The aim of the project is to address how the gyroplae ca be routiely operated for aerial recoaissace use. The side-by-side cofiguratio qualifies this type of gyroplae for demostratio flights. MTOsport (-MTOS) Figure 1: L s gyroplaes Cavalo (-MGT) The ability of a gyroplae to fly very slowly, such as miimum airspeed of 20 kts, makes it very versatile ad leads to extremely short takeoff ad ladig distaces. The possibility to (almost) stop i the air ad to desced vertically is a useful ability for observatio flights. Compared to a fixed-wig airplae the gyroplae is relatively robust with respect to atmospheric disturbaces ad ca be
41 st Europea otorcraft Forum 2015 operated safely uder very gusty coditios. I case of a egie failure the rotor state does ot chage sice it is i autorotatio cotiuously. The simplicity ad the fasciatig flyig characteristics i combiatio with the robustess ad cost efficiecy of this kid of air vehicle explai the recet boom. This has bee triggerig L to put focus o moder gyroplaes [3-6]. L s mai areas of iterest cotai the potetial improvemet of flight performace ad comfort by advaced rotor systems utilizig more tha two blades ad advaced airfoils. Additioally the reductio of parasitic drag for higher cruise speeds by utilizig advaced rotor head desigs ad miimized fuselage drag are subjects of ivestigatio. The research results are valuable for maufacturers with respect to overall system desig ad the developmet of larger gyroplaes with sigificatly higher performace ad edurace. These advaced gyroplaes may take over several flyig tasks i the future. The objective of this paper is to ivestigate the ifluece of rotor blade cotamiatio o the flight performace of a gyroplae. This ivestigatio cotributes to further uderstad potetial improvemets for future gyroplae developmets. 2. GYOLANE TECHNOLOGY The gyroplae s appearace is quite similar to a helicopter. This is maily due to the rotor system geeratig the lift force eeded for flight. O the other had it has compoets of a airplae like the ladig gear, the tailplaes icludig a rudder as well as a egie providig forward thrust by a propeller. Its operatio is similar to a airplae with a (short) takeoff ru ad a ladig approach with a flare maeuver before touchdow. 2.1. otor System The rotor system of today s lightweight gyroplaes is of sigificatly lower complexity tha that of a helicopter, sice o trasmissios, gearboxes, tail rotors or driveshafts are eeded. A teeter head rotor system is used which is commoly kow as seesaw rotor, Figure 2. By cotrol stick movemets the rotor head ca be tilted aroud the pitch pivot bolt (B) i order to tilt the rotor lift force forwards ad backwards. Furthermore it ca be moved aroud the roll pivot bolt (B) to cotrol the attitude of the rotor lift force for rollig maeuvers. Figure 2: Gyroplae tiltig rotor system (AutoGyro s MTOsport) A tower block provides the attachmet of the rotor to the rotor head by a cetral flappig hige called teeter bolt (TB). This flappig hige provides the freedom for the etire rotor to flap aroud the TB i order to compesate for asymmetric airflow ad the resultig asymmetric lift distributio. A peumatic trim system provides additioal cotrol forces i order to improve flight comfort. A prerotatio system allows a acceleratio of the rotor to a speed of about 200 rpm before iitiatig the takeoff ru. The rotor blade airfoil utilized i several gyroplaes is the NACA 8-H-12 which is discussed i this paper. The rotor blades are coected to the rotor head with a fixed icidece agle. No collective blade cotrol is available. 2.2. Airframe The gyroplae airframe cosists of the fuselage, the tailplaes, the egie ad propeller, the ladig gear ad the cotrol system. Gyroplaes with ope ad closed fuselages are available o the market. The horizotal tailplae without elevator is eeded for icreased pitch dampig i order to improve flight stability. The yawig movemet of the gyroplae is cotrolled by a rudder like i a airplae. This is used to maitai coordiated flight by compesatig yawig momets due to propeller slipstream effects ad to perform crosswid ladigs. The egie ad propeller of today s gyroplaes are typically istalled as pusher cofiguratios. This allows a almost free visio i forward directio. The throttle is covetioal to most powerplats ad provides the meas to icrease or decrease egie power ad thus, propeller thrust. The ladig gear cotais two mai wheels ad a ose wheel, which is steerable ad coected to the pedals. The mai wheels cotai the brakes. The rotor cotrol system cosists of rods or cables trasmittig the cotrol stick movemets to the rotor head.
41 st Europea otorcraft Forum 2015 2.3. Techical ata Some basic data of L s gyroplaes are preseted i Table 1. Cavalo -MGT MTOsport -MTOS MTOW [kg] 500 450 Egie power [hp] 115 100 otor diameter [m] 8.4 8.4 ade chord [m] 0.2 0.2 ade icidece agle [ ] 2.5 2.5 Cruise speed [kt] 60 60 Table 1: Techical data of L s gyroplaes 3. GYOLANE FLIGHT HYSICS The followig sectios explai the basics of autorotatio durig vertical descet ad forward flight as well as the drag force i cruise flight. 3.1. Vertical Autorotatio Autorotatio is the self-sustaied rotatio of the rotor without the applicatio of ay shaft torque. The eergy to drive the rotor is provided by the relative airstream. urig a vertical autorotatio, two basic compoets cotribute to the relative wid strikig the rotor blades [1]. The upward flow through the rotor system remais relatively costat over the radial directio. It depeds o the vertical descet rate of the rotor ad the rotor-iduced velocity. The horizotal velocity compoet at the midpoit of a local blade sectio is depedig o the rotor rotatioal speed ad the radial positio of the sectio. It is zero at the rotor shaft ad reaches its maximum at the blade tip. The local lift ad drag forces are depedig o the local flow velocity ad the agle of attack (AoA). urig vertical descet the local AoA is decreasig i radial directio. This geerates regios of the rotor disc that create the forces ecessary for autorotatio. The ier regio, characterized by higher local AoA, creates drivig aerodyamic force compoets due to forward tilted vectors of the resultig aerodyamic force, Figure 3. The outer regio creates drive aerodyamic force compoets leadig to a equilibrium state. Figure 3: egios of drivig ad drive aerodyamic forces (vertical autorotatio) The outer regio with relatively smaller local AoA but higher velocities geerates a aerodyamic force with a larger vertical compoet producig the majority of the rotor lift. 3.2. Autorotatio i Forward Flight I forward flight, a additioal compoet of the airspeed cotributes to the relative wid strikig the rotor blades. To prevet imbalaced liftig forces the rotor head is costructed such that the blades ca flap. Oe or more teeter joit(s) is/are utilized for this purpose. The advacig blade flaps up, decreasig the AoA, while the retreatig blade flaps dow, icreasig the AoA. This leads to the effect that almost the etire retreatig regio is drivig ad the advacig regio is drive durig cruise flight, Figure 4.
41 st Europea otorcraft Forum 2015 G F Weight force actig i the ceter of gravity (CG) vertically dowwards. otor force actig i the teeter bolt (TB) vertically to the rotor plae upwards. arasitic drag force actig i the ceter of gravity parallel to the airflow backwards. It cotais the drag from everythig but the rotor blades, such as the fuselage, the gear, the tail, the rotor mast, the fittigs, the rotor head, etc. F eller force actig i the propeller shaft parallel to the logitudial axis forwards. The rotor force forces: F is separated ito lift ad drag Figure 4: egios of drivig ad drive aerodyamic forces (cruise flight) 3.3. rag Force i Cruise Flight The forces actig o the gyroplae durig steady state horizotal cruise flight are preseted i Figure 5. At a airspeed V = 60 kt the logitudial axis of the gyroplae may be cosidered to be almost parallel to the groud. L otor lift force: part of the rotor force actig vertically to the airflow upwards. otor drag force: part of the rotor force actig parallel to the airflow backwards. The total gyroplae drag force is due to the rotor ad the parasitic part: = +. (1) The parasitic drag force is: ρ 2 (2) = V S C. 2 The rotor drag force arises by the tiltig of the rotor force backwards due to the rotor AoA. Assumig that the rotor force acts approximately perpedicular to the rotor plae [10] the rotor drag force is: = F si α F α. (3) Neglectig the relatively small vertical force actig o the horizotal tail ad the small rotor AoA durig steady state cruise flight, the rotor force ca be assumed to be almost equal to the weight force: (4) F G. Figure 5: Forces actig o the gyroplae durig steady state horizotal cruise flight (horizotal tail lift force eglected) I this flight coditio the lift force of the horizotal tail may be eglected; hece five importat forces are cosidered to act o the gyroplae: With this the total gyroplae drag force is: ρ 2 (5) V S C + G α. 2 For steady state flight the propeller force must be equal to the total drag force:
41 st Europea otorcraft Forum 2015 (6) F r 2 = V S C + G α. 2 It is obvious that durig low-speed flight the rotor drag force is domiat due to the high rotor AoA at this flight state. At higher airspeeds the parasitic drag force becomes more relevat for the overall drag force. 4. GYOLANE SIMULATION MOEL A overall simulatio model of the MTOsport gyroplae is available at L. The simulatio model is implemeted i MATLAB/Simulik ad cotais subsystems for the rotor, the body, the ladig gear, the cotrol system, the egie ad the propeller. The rotor is calculated by the strip method, such that the idividual airflows ad aerodyamic forces at te blade elemets are computed. The rotor blades are cosidered to be rigid. The rotor-iduced velocity is a fuctio of rotor force, rotor disk area ad airspeed ad -directio. The rotor rotatioal speed is determied by a first-order differetial equatio based o the rotatioal momet of both blades. The flappig motio of the rotor blades is cosidered as well as geeric aerodyamic effects due to Mach umber ad tip loss. The total aerodyamic forces ad momets of the gyroplae body icludig mast ad tailplaes are determied. A ladig gear model is available as well as a model of the cotrol system providig the stick force/deflectio relatio. A egie model of the otax 912 is available providig propeller thrust depedig o propeller rotatioal speed ad airspeed beeath others. The simulatio model of the MTOsport has bee validated with fight test data. For this purpose the MTOsport (-MTOS) has bee equipped with a special flight test istrumetatio (FTI), Figure 6. The measured flight parameters were sufficiet to fully uderstad the etire flight state of the gyroplae body ad rotor. Iertial data, cotrol deflectios ad forces, airflow data as well as rotor ad propeller rotatioal speed were recorded. I order to deliver high quality measuremets of the airflow a ose boom with a legth of more tha two meters has bee istalled. At its tip special vaes for measurig agle of attack ad sideslip have bee istalled. The flight test data were utilized to validate the simulatio model of the MTOsport. The simulatio model matches the flight test data adequately for several maeuvers like steady state flights i the etire airspeed rage, dyamic maeuvers i the roll, pitch ad yaw axes as well as acceleratio ad deceleratio flights [3]. The simulatio model is part of the gyroplae flight simulator operated at L, Figure 7. Figure 7: L s gyroplae flight simulator This flight simulator is used for pilot traiig ad hadlig qualities studies of ew developmets. 5. EFFECTS OF OTO CONTAMINATION 5.1. Flight Trials Figure 6: MTOsport gyroplae with special flight test istrumetatio durig flight test I order to quatify the effects of rotor cotamiatio flight trials with the MTOsport gyroplae were coducted. The gyroplae was flow with cotamiated ad clea rotor blades withi oe hour. No atmospheric differeces betwee the two flights were oticeable. Figure 8 shows the level of rotor blade cotamiatio by isects. This is a typical look of the rotor blades after flight i the summer period. It may look like this or eve worse after less tha oe hour of flight time.
41 st Europea otorcraft Forum 2015 Figure 8: Gyroplae rotor blade cotamiated by isects I both flights the gyroplae has bee trimmed at a airspeed of V 60 kt while the egie ad rotor rotatioal speeds have bee measured. The basic results obtaied from these two flights are summarized i Table 2: otor V [kt] [rpm] [rpm] Clea 60 4400 350 Cotamiated 60 4600 350 For this purpose a calculatio usig XFOIL, Versio 6.94 [8], has bee coducted at differet airspeeds for the two cases 1. Clea : lamiar-turbulet trasitio poit free (meas to be determied by XFOIL) ad 2. Cotamiated : lamiar-turbulet trasitio poit fixed at 7 % of the blade chord. The fixed trasitio poit represets a turbulet boudary layer over early the etire surface due to the cotamiatio. The trasitio from lamiar to turbulet is forced at 7 % of the blade chord at the upper ad the lower surface. This is quite far upstream i compariso to the free trasitio poit calculatio where the airflow is lamiar up to about 50 % of chord o the upper surface ad to 100 % of chord o the lower surface depedig o eyolds umber ad AoA. The fixatio o 7 % of the blade chord is based o log term experiece i the field of lamiar-turbulet trasitio research [9]. Figure 9 presets the computatioal results for a eyolds umber of 1.9 millio ad a Mach umber of 0.41. This case correspods to a rotor blade local velocity of about V 270 kt ad a blade chord of 0.2 m of the MTOsport rotor. This represets the average eyolds umber for cruise at about 90 % radial positio ad a typical rotor rotatioal speed of 350 rpm. Table 2: Flight test results with clea ad cotamiated rotor I order to maitai altitude the egie rotatioal speed has to be icreased by about 200 rpm due to the rotor cotamiatio. (Note: this is the egie rotatioal speed; the propeller rotatioal speed is lower by the factor 0.41 due to gearig). The rotor rotatioal speed is ot affected by the rotor blade cotamiatio. 5.2. Aalysis For the aalysis of the rotor cotamiatio effects the MTOsport simulatio model has bee used combied with a 2 airfoil calculatio. 5.2.1. Airfoil Aerodyamic Characteristics The aerodyamic characteristics of the NACA 8-H- 12 airfoil based o wid tuel tests are published i [7]. However, the effects of cotamiatio are ot available. Figure 9: Computed aerodyamic characteristics of the NACA 8-H-12 airfoil, 2 calculatio (eyolds umber of 1.9 millio, Mach umber of 0.41) It appears that the drag coefficiet C computed with a fixed trasitio poit is almost doubled i the relevat regio of local lift coefficiets: C 0.3...1.0. L Accordig to this calculatio, the airfoil produces about 100 % more drag due to turbulet boudary layer caused by this cotamiatio.
41 st Europea otorcraft Forum 2015 Furthermore, the lift curve slope with respect to rotor blade local AoA is reduced by about 15 % i the case of fixed trasitio, represetig the cotamiated case. I case of stroger rotor blade cotamiatio further degradatio with respect to drag ad maximum lift coefficiets may occur. 5.2.2. Simulated Cruise Flight The simulatio model of the MTOsport gyroplae has bee used to ivestigate the impact of rotor cotamiatio o flight performace. Stadard atmosphere ad a total aircraft mass of m = 450 kg were assumed. With these assumptios the simulatio model has bee trimmed at a airspeed of V = 60 kt usig the aerodyamic characteristics preseted i Figure 9. I both cases, i.e. clea ad cotamiated, the rotor force is F G 4414 N. It ca be assumed that the parasitic drag force remais uchaged due to cotamiatio. With the parasitic drag area of S = 1.0 m² ad a parasitic drag coefficiet of C = 1.0 a parasitic drag force of is obtaied at = 573 N V = 60 kt accordig to eq. (2). Table 3 presets the trim results based o the simulatio model for the clea ad cotamiated cases. Clea Cotamiated [rpm] 347 348 α [ ] 6.2 8.1 [rpm] 4401 4596 [N] 478 624 [N] 573 573 F [N] 1051 1197 L/ [1] 4.2 3.7 Table 3: MTOsport simulatio model trimmed at a airspeed of V = 60 kt for clea ad cotamiated rotor The egie rotatioal speed is icreased by = 195 rpm which fits the flight test results very well. The differece of propeller thrust eeded for steady state flight is: F = 1197 N 1051 N = 146 N. This meas a relative icrease of about 14 % due to the cotamiatio. It ca be assumed that the fuel cosumptio would rise by the same amout. Obviously, the rotor blade local AoA is also icreased due to the cotamiatio. At a give airspeed it depeds o the blade azimuth agle ad the radial positio. Figure 10 shows the rotor blade local AoA i cruise flight at a radial positio of about 90 % of the rotor radius. Figure 10: otor blade local AoA at a radial positio of about 90 % of rotor radius i cruise flight coditio The blade azimuth agle is defied to be zero whe the rotor blade is at the rear positio. For the clea case the maximum rotor blade local AoA is about α 5. 9 for the retreatig blade ( ψ = 270 ). For the cotamiated case α 6. 7 is obtaied. This cofirms the eed for higher rotor AoA for the cotamiated case. 5.2.3. Simulated Takeoff The takeoff procedure to be applied for a gyroplae with a tiltig rotor system is as follows: (1) rerotate up to a sufficiet rotor rotatioal speed ( = 200 rpm ) while the cotrol stick is i full forward positio. (2) elease the wheel brake. (3) Move the cotrol stick to full aft positio. (4) Apply full throttle.
41 st Europea otorcraft Forum 2015 (5) Accelerate o groud. (6) Cotrol pitch agle via cotrol stick durig takeoff. (7) Accelerate i flight up to about V = 50 kt ad climb. The takeoff acceleratio with the rotor disc tilted aft allows airflow through the blades to accelerate the rotor. After takeoff the pilot eeds to push the cotrol stick forward i order to lower the rotor AoA ad cotrol the pitch attitude. For the MTOsport a prerotatio up to = 200 rpm is eeded i order to avoid the so called blade flappig. This pheomeo is caused by too low rotor rotatioal speed at too high airspeed ad ca be catastrophic. For the simulatio of the complex takeoff procedure a simple pilot model has bee used i order to obtai comparable results for the clea ad cotamiated cases. I both cases (clea ud cotamiated) a iitial rotor rotatioal speed of = 200 rpm is assumed. The cotrol stick i full aft positio results i a rotor head pitch cotrol agle of η =15. Assumig the logitudial axis of the gyroplae to be parallel to the groud, the rotor AoA durig the takeoff acceleratio o the ruway is: (8) a = η H + β. max urig takeoff ad oce airbore the rotor head agle is lowered by the pilot model for pitch cotrol. By this the rotor AoA is lowered as well. The maximum takeoff thrust of the MTOsport egie (otax 912) is about F 2000 N. Figure 11 presets the results of a simulated takeoff ru of the MTOsport with clea rotor. Stadard atmosphere ad o wid were assumed. The takeoff roll distace of the MTOsport with clea rotor is about s TO 121m accordig to this simulatio. The distace to pass 15 m height above groud is s 218 15 m. These values correspod well with flight experiece. H Figure 11: Simulated takeoff ru with clea rotor (mass 450 kg) The MTOsport is takig off at a airspeed of V = 43 kt. At 15 m height the gyroplae has accelerated to V = 51kt. Its rotor rotatioal speed rises from = 200 rpm after prerotatio to 300 rpm at takeoff ad 350 rpm durig steady state cruise flight. The maximum flappig agle is obtaied shortly before takeoff. Its value β max = 3, 5 is well below the flappig hige stops of approximately 7. The takeoff simulatio has also bee coducted with the cotamiated rotor. The results are preseted i Table 4. Clea Cotamiated s TO [m] 121 144 s 15 [m] 218 253 β [ ] 3.5 4.2 max Table 4: Simulated MTOsport takeoff performace with clea ad cotamiated rotor The takeoff roll distace is icreased by about 20 % due to rotor cotamiatio. The distace to pass the 15 m height is icreased by about 16 %. Iterestig to ote is that the maximum flappig agle is icreased by 20 % to β max = 4. 2. Hece the margi to the flappig hige stops is reduced.
41 st Europea otorcraft Forum 2015 6. ISCUSSION The aalysis highlights the sigificat effect of rotor cotamiatio o gyroplae flight performace. The drag created by the NACA 8-H-12 airfoil is icreased by about 100 % due to the cotamiatio ivestigated herei. This immese aerodyamic degradatio leads to a overall performace loss of the gyroplae by about 14 % with respect to cruise flight performace ad up to 20 % loger takeoff distace. It appears that gyroplae flight performace could be improved by eve loger lamiar airflow o the airfoil. However, rotor cotamiatio caot be avoided sice isects are permaetly populatig the air. This makes the approach to achieve loger lamiar airflow questioable. For a compariso the helicopter airfoil NACA 23012 has bee calculated usig XFOIL with the iput data preseted i sectio 5.2.1. Table 5 presets the results for a local rotor blade lift coefficiet of C = 0.8. L Free Fixed NACA 8-H-12 C = 0. 006 C = 0. 012 NACA 23012 C = 0. 008 C = 0. 012 Table 5: otor local drag coefficiets calculated with XFOIL for fixed ad free trasitio (eyolds umber 1.9 millio, Mach umber 0.41) The degradatio due to cotamiatio of the NACA 23012 airfoil is oly 50 % istead of 100 % i case of the NACA 8-H-12. The aerodyamic quality of the NACA 8-H-12 clea airfoil is very high eve though it is a quite old desig. There might be optios to improve the gyroplae performace by airfoil optimizatio, but its robustess agaist cotamiatio is a issue. Istead gyroplae maufacturers might obtai sigificat cruise flight performace beefits by 1. reducig the parasitic drag force ad/or 2. addig a fixed wig. I order to reduce the parasitic drag force a redesig of all obviously aerodyamic ufavorably shaped parts like the rotor head, the mast or the gear is eeded. Aother approach is the uloadig of the rotor by a additioal fixed wig producig lift. A additioal wig ca miimize the overall drag drastically i the itermediate velocity rage. Calculatios for a represetative gyroplae with a additioal wig of just 1.7 m² area show a reductio of about 12 % total drag at cruise speed [6]. 7. CONCLUSIONS The aalysis preseted herei improved the uderstadig of gyroplae flight performace, particularly the ifluece of rotor airfoil aerodyamic quality o air vehicle flight performace. Based o these results the followig coclusios ca be draw 1. otor blade cotamiatio by isects may lead to sigificat performace degradatios. The propeller thrust i cruise flight is about 14 % higher. The takeoff distace raises more tha 16 %. 2. L s gyroplae simulatio model is capable to assess idividual rotor aerodyamic effects o overall aircraft level. 3. The NACA 8-H-12 airfoil used i most of today s gyroplaes has a high aerodyamic quality if the surface is clea. 4. Further reductio of rotor blade airfoil drag by eve loger lamiar airflow might be ullified by cotamiatio which i practice caot be avoided. 8. SYMBOLS AN ABBEVIATIONS Greek symbols α otor agle of attack [ ] α otor blade local agle of attack [ ] β max Maximum flappig agle [ ] ε otor blade icidece agle [ ] η H otor head pitch cotrol agle [ ] ψ otor blade azimuth agle [ ] Lati symbols C otor blade local drag coefficiet [-] C L otor blade local lift coefficiet [-] C Gyroplae parasitic drag coefficiet [-] Total gyroplae drag force [N] Gyroplae parasitic drag force [N] otor drag force [N] F eller force [N] F G L otor force vertical to rotor plae [N] Weight force [N] otor lift force [N]
41 st Europea otorcraft Forum 2015 Egie rotatioal speed [rpm] r S s 15 TO otor rotatioal speed [rpm] otor radius [m] arasitic drag area [m²] istace to pass 15 m obstacle [m] s Takeoff ru distace [m] V V Airspeed [kt] otor blade local velocity [kt] X otor blade local horizotal force [N] Z otor blade local vertical force [N] Abbreviatios AoA CG L FTI MTOW B B TB Agle of Attack Ceter of Gravity eutsches Zetrum für Luft- ud aumfahrt (Germa Aerospace Ceter) Flight Test Istrumetatio Maximum Takeoff Weight itch ivot Bolt oll ivot Bolt Teeter Bolt THW Techisches Hilfswerk (Germa Federal Agecy for Techical elief) Simulatio esearch, 24th SFTE-EC Symposium, Brauschweig, 2013. [6] Sachs, F., uda, H., Seewald, J., Leistugssteigerug vo Tragschrauber durch Starrflügel, eutscher Luft- ud aumfahrtkogress, Augsburg, 2014. [7] Schaefer,. ad Smith, H. A., Aerodyamic Characteristics of the NACA 8-H-12 Airfoil, NACA TN 1998, Lagley, 1949. [8] rela, M., XFOIL: A Aalysis ad esig System for Low eyolds Number Airfoils, MIT ept. of Aeroautics ad Astroautics, Cambridge, Massachusetts, USA, 1989. [9] Harris, C., Two-imesioal Aerodyamic Characteristics of the NACA 0012 Airfoil i the Lagley 8-Foot Trasoic ressure Tuel, NASA TM 81927, Lagley, 1981. [10] routy,. W., Helicopter Aerodyamics - ay routy s otor ad Wig Colums 1979-1992, Helobooks, a uit of Mojave Books LLC, Mojave CA, 2004. 9. EFEENCES [1] Leishma, J. G., evelopmet of the Autogiro: A Techical erspective, Joural of Aircraft, Vol. 41, No. 4, pp. 765-781, 2004. [2] Harris, F.., Itroductio to Autogyros, Helicopters, ad Other V/STOL Aircraft, Volume I: Overview ad Autogyros, NASA/S 2011-215959 Vol I, Moffett Field, 2011. [3] ruter, I. ad uda, H., A ew Flight Traiig evice for Moder Lightweight Gyroplaes, America Istitute of Aeroautics ad Astroautics, AIAA Modelig ad Simulatio Techologies Coferece, ortlad, 2011. [4] uda, H., ruter, I., eiler, C., Oertel, H., Zach, A., Gyroplae Logitudial Flight yamics, 3rd CEAS Air & Space Coferece, Veice, 2012. [5] uda, H., Seewald, J., Cremer, M., ata Gatherig for Gyroplae Flight yamics ad