The low density of the Martian atmosphere and the relatively small Mars Helicopter rotor result in very low chord-based Reynolds number flows, Re O(103 104). Objective function is chosen as a combination expression of non-dimensional required power in hover and forward flight. The present research provides a performance comparison between several low Reynolds number airfoil profiles for the Mars Helicopter. The trim condition must be attainable in any flight condition. Aerodynamic constraints consist of limits on power available in hover and forward flight, aerodynamic requirements (lift, drag and moment coefficients) for critical flow condition occurring on rotor blades. The design variables include twist, taper ratio, point of taper initiation, blade root chord, and coefficients of the airfoil distribution function. Airfoil characteristics are automatically generated by an analysis tool where lift, drag, and moment coefficients of airfoil are predicted for subsonic to transonic flow and a wide range of attack angles. An airfoil is any surface that produces a useful aerodynamic force. The optimization process was constructed by integrating several programs developed by the author. With this approach, airfoil shape was considered in terms of design variables.
An advanced geometry representation algorithm which uses the Class Function/Shape Function Transformation (CST) is employed to generate airfoil coordinates. This study proposes a process to obtain an optimal helicopter rotor blade shape including both planform and airfoil shape for helicopter aerodynamic performance in forward flight.