Glider Polar Curve & MacCready Speed Simulator Back EN · ZH
Glider Aerodynamics

Glider Polar Curve & MacCready Speed Simulator
Polar · MacCready Speed · Cross-Country

Real-time calculation of glider polar curve, best glide speed, minimum sink speed, and MacCready optimal speed. Adjust thermal strength and wind to optimize cross-country performance.

Glider Parameters
Glider Presets
Wing Loading W/S 35.0 kg/m²
Zero-Lift Drag CD0 0.0100
Induced Drag Factor k = 1/(πARe) 0.0140
Thermal Climb Rate w 2.0 m/s
0: none / 2: moderate / 5: strong thermal
Wind Speed (tailwind +) 0 km/h
Thermal Spacing 30 km
Starting Altitude 1500 m
Best Glide Ratio L/D
Best Glide Speed [km/h]
Min Sink Rate [m/s]
Min Sink Speed [km/h]
MacCready Optimal Speed [km/h]
Cross-Country Speed [km/h]

Theory

Sink rate (as a function of speed): $V_s = \dfrac{C_{D0}}{2K}\cdot\dfrac{W/S}{0.5\rho V} + \dfrac{2K(W/S)}{0.5\rho V}$

Best glide ratio: $(L/D)_{max} = \dfrac{1}{2}\sqrt{\dfrac{\pi AR\, e}{C_{D0}}}$

MacCready optimal speed: tangent from the $w_{thermal}$ point on the polar curve

Cross-country speed: $V_{XC} = \dfrac{d}{t_{glide} + t_{thermal}}$

CAE Integration: Aerodynamic design and XFOIL/AVL analysis verification for low-speed, high-aspect-ratio airfoils. Also applicable to efficiency evaluation of fixed-wing drones and HAPS (High-Altitude Platform Stations).