Utafiti uliotengenezwa na Radimir Y. Yanev na Ingo Staack unawasilisha mfumo jumuishi wa sizing na performance analysis ili kutathmini kwa haraka konfiguresheni nyingi tofauti katika conceptual design ya electric vertical take-off and landing (eVTOL) aircraft. Method inaunganisha geometric sizing ya vehicle components, flight mission analysis, battery sizing kulingana na power na energy requirement, pamoja na component-based mass estimation ndani ya iterative loop ileile. Katika verification results, mean absolute percentage error ilikuwa %7,5 kwa rotor/propeller solidity na %8,0 kwa hover power; battery discharge model ilipolinganishwa na experimental data ilionyesha deviation ya takriban %5 katika discharge depth ya new cell na chini ya %1 katika end-of-life condition. Katika vehicle-level comparison na NASA reference designs, maximum take-off mass deviation ilikuwa %0,6 kwa Quadrotor na %3,2 kwa Lift + Cruise.

Ujumbe mkuu wa utafiti ni kwamba low-fidelity modeling approach inayohifadhi physical relationships inaweza kutumika kupunguza kwa haraka early eVTOL design space. Hata hivyo, method haijatengenezwa kwa final aerodynamic design, detailed structural verification, certification au real flight performance. Propeller model haisuluhishi kwa kina higher-order aerodynamic effects kama tip losses, non-uniform flow, rotor–wing na rotor–rotor interactions; battery model pia haimodeli moja kwa moja temperature, aging, cell balancing na degradation mechanisms.

Jambo muhimu katika utafiti kwa upande wa eVTOL design ni kwamba hauangalii total battery energy pekee. Energy requirements za high-power sections kama vertical take-off, transition flight na landing, pamoja na cruise flight, zinakokotolewa katika mission profile ileile. Hasa katika landing phase, wakati battery state of charge imepungua na high power inahitajika tena, inaonyesha kwamba battery sizing kwa Wh/kg pekee huenda haitoshi.

Ni tatizo gani kuu katika eVTOL design?

Distributed electric propulsion systems huunda configuration space pana zaidi kuliko classic helicopter au fixed-wing aircraft. Katika eVTOL design, rotor count, rotor diameter, wing geometry, matumizi ya separate au shared propulsion elements kwa vertical flight na cruise, battery size, motor power, mission range na landing-area size si independent. Kwa mfano, rotors ndogo zinaweza kupunguza vehicle footprint; lakini zinaweza kuongeza disk loading na hivyo kuongeza hover power. Higher hover power inaweza kuhitaji motor na battery kubwa zaidi; increased battery mass inaweza tena kuongeza total take-off mass.

Framework iliyotengenezwa na utafiti inashughulikia feedback design problem hii moja kwa moja. Vehicle haikokotolewi mara moja kwa fixed parameters; component sizing, mission analysis, battery sizing na mass estimation hurudiwa hadi maximum take-off mass (MTOM) na required battery capacity ziconverge.

Kwa nini propeller sizing iko katikati ya design?

Katika eVTOL inayofanya vertical flight, disk loading ya rotor au lift propellers ni mojawapo ya variables kuu zinazoathiri moja kwa moja required power katika hover. Katika utafiti, design thrust kwa kila VTOL propeller inaamuliwa kwa maximum take-off mass, gravitational acceleration, propeller count na %10 maneuver margin:

\[ T_{\mathrm{prop,des}} = \frac{k_{\mathrm{maneuver}}\,m_{\mathrm{MTO}}\,g} {N_{\mathrm{prop,VTOL}}} \]

Hapa \(T_{\mathrm{prop,des}}\) ni design thrust ya VTOL propeller moja; \(k_{\mathrm{maneuver}}\) ni maneuver margin, \(m_{\mathrm{MTO}}\) ni maximum take-off mass, \(g\) ni gravitational acceleration na \(N_{\mathrm{prop,VTOL}}\) ni propeller count inayotumika katika vertical flight.

Propeller radius huchaguliwa kuwa kubwa iwezekanavyo, lakini geometric limits za landing area na required clearance kati ya propellers huzuia ukubwa huu. Lengo la approach hii ni kupunguza disk loading na hivyo required induced power kwa hover.

Propeller power humodeliwa kama jumla ya induced power na profile power:

\[ P_{\mathrm{prop}} = \kappa T(v_i + V_z) + \rho A_d(\omega R)^3 C_{P0} \]

Katika equation hii \(\kappa\) ni induced power correction coefficient, \(T\) thrust, \(v_i\) induced velocity, \(V_z\) flow velocity katika disk-axis direction, \(\rho\) air density, \(A_d\) disk area, \(\omega\) angular speed, \(R\) propeller radius na \(C_{P0}\) profile power coefficient. Model ya utafiti inalenga conceptual design; tip losses, rotor–rotor interaction, rotor–wing interaction, non-uniform inflow na time-dependent aerodynamic effects katika transition flight hazisuluhishwi moja kwa moja.

Wing na fuselage design zinaunganishwaje na system?

Katika winged eVTOL configurations, wing huoptimishwa kwa cruise flight. Katika utafiti, wingspan huzuiliwa na landing-area geometry; wing area, aspect ratio na cruise lift coefficient huamuliwa kwa balance kati ya aerodynamic drag na structural mass. Wing area ndogo na higher aspect ratio zinaweza kuongeza aerodynamic efficiency, lakini pia zinaweza kuongeza structural mass, kwa hiyo maximum aerodynamic efficiency pekee hailengwi.

Aft fuselage na tail design pia huzingatiwa kama separate constrained optimization problem. Lengo ni kupunguza total wetted area ya aft fuselage huku horizontal na vertical tail volume coefficients, tail position, geometric convergence na tail aspect ratio limits zikitimizwa.

Battery haisizingwi kwa energy capacity pekee

Moja ya sifa za framework ni kwamba battery haiwakilishwi kwa energy density fulani ya Wh/kg pekee. Katika kila control point ya mission, required electrical power hugawanywa kwa cells; current hutatuliwa iteratively kupitia cell open-circuit voltage, under-load voltage na internal resistance:

\[ I = \frac{P_{\mathrm{demand,cell}}}{V_{\mathrm{UL}}}, \qquad V_{\mathrm{UL}} = V_{\mathrm{OC}} - R_{\mathrm{tot}} I \]

Hapa \(I\) ni cell current, \(P_{\mathrm{demand,cell}}\) ni power demand per cell, \(V_{\mathrm{UL}}\) ni under-load cell voltage, \(V_{\mathrm{OC}}\) ni open-circuit voltage na \(R_{\mathrm{tot}}\) ni total internal resistance ya cell.

State of charge husasishwa katika mission kwa Coulomb counting:

\[ SOC_{i+1} = SOC_i - \frac{I_i\Delta t_i}{C_{\mathrm{act}}} \]

\(SOC_i\) ni current state of charge, \(I_i\) current, \(\Delta t_i\) time step na \(C_{\mathrm{act}}\) effective usable cell capacity. Battery size huongezwa au kupunguzwa iteratively hadi itimize required SOC mwishoni mwa mission pamoja na power limit iliyoamuliwa na maximum C-rate.

Kwa nini mass calculation ina feedback?

Total vehicle mass huundwa kama jumla ya components badala ya historical mass fraction moja:

\[ m_{\mathrm{total}} = \sum_{i=1}^{N}m_i \]

Jumla hii inajumuisha structural elements kama wing, fuselage, tail, pylon na landing gear; propeller, electric motor na power electronics; flight control, avionics na environmental control systems; passenger na baggage payload; pamoja na battery cells na packaging additional mass. Battery inapokuwa kubwa vehicle huwa nzito, vehicle nzito huhitaji thrust na power zaidi, na hii inaweza tena kuathiri battery na motor size. Iterative solution hufunga dependency hii.

Mbinu na Matokeo ya Utafiti

Verification ilifanywa katika levels tatu tofauti

Waandishi walijaribu framework katika levels tatu tofauti badala ya kuiverify kwa vehicle example moja tu. Kwanza, propeller sizing na hover performance model zililinganishwa na real helicopter rotors pamoja na NASA eVTOL reference propellers. Pili, battery discharge model ilijaribiwa kwa experimental cell data iliyopimwa chini ya eVTOL mission profiles. Mwisho, whole-vehicle sizing loop ililinganishwa na NASA NDARC-based Urban Air Mobility reference vehicles.

Propeller validation data set

Rotor data set ilijumuisha conventional helicopters kama MBB Bo 105, Eurocopter EC 135, Aérospatiale SA 365N Dauphin na Sikorsky UH-60A Black Hawk, pamoja na rotorcraft na powered-lift eVTOL concepts mbalimbali za NASA. Rotor diameters katika data set zilibadilika kutoka 2,23 m hadi 16,36 m, hover thrust kutoka 3,8 kN hadi 73,6 kN, na hover power kutoka 54 kW hadi 1569 kW. Hivyo model haikujaribiwa kwa scale moja tu, bali kwenye vehicles zenye disk loading na rotor sizes tofauti sana.

Mean absolute percentage error ya calculated rotor solidity values dhidi ya references iliripotiwa kuwa %7,5, na kwa blade loading %7,14. Katika hover power calculation, mean absolute percentage error ilikuwa %8,0. Model ilionyesha tendency ya ku-underestimate solidity na hover power katika baadhi ya helicopter rotors zenye low disk loading, na ku-overestimate katika baadhi ya distributed propulsion systems zenye high disk loading.

Battery model ililinganishwaje na real cell experiments?

Katika battery validation, published experimental data set ya Sony-Murata 18650 VTC-6 lithium-ion cells ilitumika. Nominal capacity ya cell ni 3200 mAh, nominal voltage 3,6 V na specific energy iliyotolewa katika utafiti ni takriban 230 Wh/kg. VAH02 mission profile iliyochaguliwa ina 54 W take-off load kwa sekunde 75, 16 W cruise load kwa sekunde 1000 na 54 W landing load tena kwa sekunde 105.

Katika new-cell experiment, SOC ilishuka kutoka takriban %100 hadi %36, huku model ikitabiri final SOC ya takriban %38, na waandishi wakatathmini tofauti hii kama deviation ya takriban %5. Katika end-of-life condition, experiment ilishuka kutoka takriban %82 hadi %13 SOC, na deviation ya model results ikabaki chini ya %1.

Hata hivyo, real cell aging haikusimuliwa kimwili ndani ya model. Ili kuwakilisha end-of-life battery, utafiti ulitumia kupunguza initial SOC hadi takriban %80 kama proxy approach. Kwa hiyo matokeo hayamaanishi kwamba detailed battery-aging model imeverifywa.

Largest instantaneous difference ilionekana katika landing phase mwishoni mwa mission, ambapo SOC ni low na high power inahitajika. Maximum deviation katika instantaneous current/C-rate prediction ya model ilifikia takriban %15 katika region hii. Waandishi wanaeleza kwamba tofauti hii ni short-lived na athari yake kwenye total discharged energy ni limited.

Vehicle-level validation na NASA reference vehicles

Katika overall sizing validation, vehicles mbili zilizingatiwa. Vehicle ya kwanza ni Quadrotor wingless yenye large lift rotors nne; ya pili ni winged Lift + Cruise configuration yenye distributed lift-propellers nane na separate pusher propeller kwa cruise.

Validation mission ilifafanuliwa kwa kubeba passengers sita. Design payload ni takriban 540 kg. Mission ina flight legs mbili; katika utafiti kila leg imefafanuliwa kuwa 37,5 nautical mile, yaani takriban 70 km, na pia 20-minute cruise-power reserve hutumika. Kwa battery, pack-level effective gravimetric energy density ya 400 Wh/kg na %80 usable discharge range zilikubaliwa.

Kwa Quadrotor, calculated maximum take-off mass ni 2957 kg na NASA reference value ni 2939 kg; chanzo kinatoa deviation hii kama %0,6. Kwa Lift + Cruise, values ni 3843 kg na 3724 kg mtawalia, na reported difference ni %3,2. Empty mass deviations ziliripotiwa kuwa %1,1 kwa Quadrotor na %4,0 kwa Lift + Cruise.

Source-internal numerical inconsistency: Ingawa Table 6 inatoa Lift + Cruise MTOM values za 3724 kg na 3843 kg, explanation paragraph inayofuata inaandika absolute difference kama “79 kg”. Paragraph hiyo hiyo inadumisha value ya %3,2. Kwa hiyo absolute-difference statement si consistent na table values zake ndani ya source.

Kwa nini energy storage ndiyo sehemu kubwa zaidi ya total mass?

Katika mass breakdown ya model, energy storage ni takriban %31,9 ya Quadrotor MTOM na takriban %29,4 ya Lift + Cruise vehicle. Structural mass ni karibu robo ya total mass katika vehicles zote mbili. Katika Lift + Cruise design, share ya propulsion-system mass ni kubwa zaidi kuliko Quadrotor.

Kulingana na maelezo ya utafiti, sababu muhimu ya tofauti hii ni kwamba Lift + Cruise vehicle ina higher disk loading. Large rotors za Quadrotor hufanya kazi kwa lower disk loading, wakati small lift propellers nane za Lift + Cruise configuration zinahitaji power kubwa zaidi katika vertical flight.

Calculated hover power ya Lift + Cruise configuration ni takriban 932 kW, huku kwa Quadrotor ikiwa takriban 381 kW. Kwa upande mwingine, katika cruise flight calculated powers za vehicles mbili zinakaribiana; Quadrotor inahitaji takriban 268 kW na Lift + Cruise takriban 273 kW. Utafiti unaeleza tofauti hii kama design trade-off inayotokana na higher aerodynamic efficiency ya winged vehicle katika cruise.

Effective lift/drag indicator \(WV/P\) ni 5,4 kwa calculated Quadrotor na 8,1 kwa Lift + Cruise. Kwa hiyo winged configuration inaonekana advantageous katika cruise, lakini ina higher power requirement katika vertical flight.

Ni flight phases zipi zinaweka load kubwa zaidi kwenye battery?

Highest C-rate values katika mission zilitokea katika high-power vertical-flight segments kama hover na climb. Katika Lift + Cruise vehicle, katika first take-off hover C-rate ilikuwa takriban 1,9 kwenye takriban %95 SOC; lakini katika landing mwishoni mwa second flight leg, SOC iliposhuka hadi takriban %35, C-rate ilipanda hadi takriban 2,2 kwa high power demand ileile. Highest value ilikokotolewa kuwa takriban 2,5 katika transition climb. Katika cruise, C-rate mara nyingi ilikuwa kati ya 0,6–0,7.

Battery load ya Quadrotor ilikuwa balanced zaidi katika mission. Katika hover C-rate ilikuwa takriban 1,0, katika climb maximum takriban 1,2 na katika cruise takriban 0,6–0,7.

Battery efficiency ya Quadrotor ilibaki katika takriban %98–99 kwa sehemu kubwa ya mission. Katika Lift + Cruise vehicle ilishuka hadi takriban %96 katika high-power vertical-flight sections na ilikuwa takriban %98 katika cruise. Katika model, relative effect ya internal-resistance losses huongezeka SOC inapopungua, hivyo efficiency pia hushuka kwa power demand ileile.

Matokeo yanayoungwa mkono na utafiti

• Low computational cost, component-based na iterative method inaweza kutoa matokeo yanayoweza kutumika kwa early-stage eVTOL configuration comparisons.
• Propeller sizing model inakamata general trends za rotor solidity na hover power katika reference set iliyochunguzwa kwa mean absolute percentage error ya takriban %8.
• Simplified equivalent-circuit battery model inareproduce SOC evolution kwa karibu katika experimental VTC-6 data set kwa conceptual sizing.
• High-level MTOM na empty mass results za Quadrotor na Lift + Cruise zinakaribia NASA NDARC references ndani ya percentage points chache.
• Ingawa Lift + Cruise configuration ni aerodynamically efficient zaidi katika cruise, inahitaji power kubwa zaidi kuliko Quadrotor katika vertical flight kwa sababu ya high disk loading.
• Katika eVTOL battery sizing, high instantaneous power inayopaswa kutolewa katika low-SOC condition mwishoni mwa mission ni muhimu kama total energy.

Matokeo ambayo utafiti hauungi mkono au haujajaribu moja kwa moja

• Framework results haziwezi kutafsiriwa kama production-ready au certification-ready final eVTOL design.
• Real prototype flight test au real urban eVTOL operation haikufanywa.
• Propeller model haisuluhishi tip losses, rotor–rotor interaction, rotor–wing interaction na detailed time-dependent aerodynamics ya transition flight.
• Battery temperature, real aging mechanisms, cell balancing na degradation hazimodeliwi moja kwa moja.
• Noise, certification safety, detailed flight dynamics na control derivatives hazijaverifywa holistically.
• Kwa kuwa utafiti hauna airspace, vertiport, infrastructure, cost au operational data maalum ya Uturuki, hautoi commercial au operational suitability conclusion kwa Uturuki.

Maelezo ya Chanzo na Mbinu

Aina ya chanzo na publication status: Utafiti huu ni peer-reviewed research/modeling article. Ulichapishwa katika jarida la Aerospace mwaka 2026 kama volume 13, issue 7, article 566. Si preprint.

Utafiti asilia: Radimir Y. Yanev na Ingo Staack, “Framework for Rapid eVTOL Aircraft Configuration Design: Methodology and Verification”. DOI: 10.3390/aerospace13070566.

Corresponding author: Radimir Y. Yanev.

Taasisi: Institute of Aircraft Design and Lightweight Structures, Technische Universität Braunschweig, 38108 Braunschweig, Ujerumani.

Method class: Utafiti ni conceptual aircraft design and verification work inayounganisha low-fidelity, physics-based na semi-empirical submodels. Propeller model hutumia momentum theory na simplified blade-element approach; battery model hutumia equivalent electrical circuit; structure na system masses hutumia combination ya physics-based na semi-empirical mass-estimation methods.

Verification: Propeller model ililinganishwa na conventional helicopter rotors na NASA eVTOL designs; battery model na experimental Sony-Murata VTC-6 cell data; whole-vehicle sizing na NDARC results za NASA UAM reference Quadrotor na Lift + Cruise vehicles.

Kikomo kikuu: Lengo la framework si final vehicle certification au high-fidelity flight-physics analysis, bali ku-scan conceptual design space kwa haraka. Aerodynamic interactions, battery thermal and aging processes na baadhi ya system-level details zimerahisishwa.

Source-internal inconsistency note: Katika Source Table 6, Lift + Cruise MTOM values ni 3724 kg na 3843 kg, lakini paragraph inayofuata inaeleza difference kama 79 kg. Text ileile inaripoti %3,2 deviation. Kwa kuwa numerical inconsistency hii ipo katika source, haijasahihishwa kimya kimya.

Ufadhili: Utafiti uliungwa mkono na PEANUT na AIRDRIVE projects ndani ya German Aviation Research Program chini ya German Federal Ministry for Economic Affairs and Energy. Open-access publication fee ililipwa na open-access funds za Technische Universität Braunschweig.

Data availability: Waandishi wanaeleza kwamba final data iliyowasilishwa katika utafiti inapatikana kwa request kutoka corresponding author.

Conflict of interest: Waandishi hawakuripoti conflict of interest.

AI-use declaration: Waandishi wameeleza kwamba wakati wa kuandaa makala walitumia ChatGPT GPT-5.3 Instant kwa language improvement na kwa development ya code iliyotumika katika graph generation; walireview na kuedit outputs wenyewe na kuchukua responsibility kwa publication content. Declaration hii si scientific validation method, bali transparency statement kuhusu publication process.

License: Makala imechapishwa open access chini ya Creative Commons Attribution (CC BY) license.

Chanzo rasmi: https://doi.org/10.3390/aerospace13070566