Rotor Performance Calculator

Calculator to calculate rotor performance for helicopter, propeller and wind turbine applications. This tool also comes as an executable for download.

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Air Density, ρ_air: Unit:

Rotor RPM, Ω:

Rotor Radius, R: Unit:

Vertical Advance Ratio, λ_C:

Solidary Ratio, σ:

Airfoil Angle of Attack, α_C: Unit:

Number of Rotors, N:

Airfoil Lift Slope, a: Unit:

Airfoil Drag Factor, K:

Airfoil Zero Lift Drag Coefficient, C_D0:

Forward Flight Input values:

Forward Advance Ratio (Advance Ratio), μ_forward:

Rotor Twist Attack (deg), θ_TW:

Rotor Longitudinal Cyclic Pitch (deg), θ_1S:

Rotor Laterial Cyclic Pitch (deg), θ_1C:

Flap hinge spring stiffness (Nm), k_β:

Blade inertia (kgm²), I_blade:

No of Inflow Iterations, N_Inflow:

No of Forward Flight Iterations, N_Forward:

h is distance of C.G. below Hub, W is helicopter weight

x(C.G.) is distance the C.G is forward from Hub, y(C.G.) is distance the C.G is to right of the Hub

M_YF is aerodynamic pitch moment about the C.G, M_XF is aerodynamic roll moment about the C.G

f is the eqivalent drag area of helicopter fuselage and hub, D/(1/2ρV²), A is the rotor disk area, πR²

Helicopter Parasite Drag Area Ratio, f/A:

Helicopter Drag to Weight Ratio, D/W:

h to R Ratio, h/R:

x(C.G.) to h Ratio, x_CG/h: M_YF to W*h Ratio, M_YF/Wh:

Helicopter Sideforce to Weight Ratio, Y_FW/W:

y(C.G.) to h Ratio, y_CG/h: M_XF to W*h Ratio, M_XF/Wh:

Inflow, λ:

Dimensionless natural frequency, ν_β = 1.15 for hingeless rotors

Dimensionless natural frequency, ν_β = 1 for articulated rotors

Locke No, γ_blade = 5 to 7 for hingeless rotors; Locke No, γ_blade = 8 to 10 for articulated rotors

Dimensionless natural frequency, ν_β: Locke No, γ_blade:

Rotor Pitch, θ: Unit:

Thrust Coefficient, C_T:

Side Force Coefficient, C_Y:

Power Coefficient, C_P:

Thrust, T: Unit:

Power, P:

Efficiency:

Helicopter Efficiency:

Rotor Flow State

Advance Ratio

Inflow

Pitch (deg)

Power Coefficient

Efficiency

Hover Efficiency

V_c/v_h

v/v_h(Normal and Vortex Ring)

v/v_h(Windmill Break)

v/v_h(Turbulent Wake)

v/v_h(Autorotation)

Forward Flight Performance Results:

ν_β = Dimensionless natural frequency, γ_blade= Locke No, θ₀ = Pitch Angle (deg), λ = Inflow

C_T = Thrust Coefficient, C_H = Rotor Drag Coefficient, C_Y = Rotor Sideforce Coefficient, C_P = Power Coefficient

α_rotor = Rotor Angle of Attack, φ_rotor = Rotor Roll Angle

α_shaft = Rotor Shaft Angle of Attack, φ_shaft = Rotor Shaft Roll Angle

β₀ = Collective Flap Angle, β_1c = Longitudinal Flap Angle, β_1s = Laterial Flap Angle

(β_1c)_HP = Longitudinal Flap Angle (Hub Plane), (β_1s)_HP = Laterial Flap Angle (Hub Plane)

(θ_1s)_HP = Longitudinal Cyclic Pitch Angle (Hub Plane), (θ_1c)_HP = Laterial Cyclic Pitch Angle (Hub Plane)

θ₀

Error: λ

C_T

C_H

C_Y

C_P

α_rotor

φ_rotor

α_shaft

φ_shaft

β₀

β_1c

β_1s

(β_1c)_HP

(β_1s)_HP

(θ_1s)_HP

Error: (θ_1s)_HP

(θ_1c)_HP

Error: (θ_1c)_HP

References:

[1] http://www.eiteog.com/EiteogBLOG/No4EiteogBlogThrust.html

[2] http://www.eiteog.com/EiteogBLOG/No11EiteogBlogThrust.html

[3] http://www.eiteog.com/EiteogBLOG/No16EiteogBlogThrust.html

[4] Helicopter Theory, Wayne Johnson, 1980, Dover Publications

[5] Rotary Wing Aerodynamics, W. Z. Stepniewski and C. N. Keys, 1979, Dover Publications

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Disclaimer: Eiteog makes every effort to provide information which is as accurate as possible. Eiteog will not be responsible for any liability, loss or risk incurred as a result of the use and application of information on its website or in its products. None of the information on Eiteog's website or in its products supersedes any information contained in documents or procedures issued by relevant aviation authorities, manufacturers, flight schools or the operators of aircraft, UAVs.