Optimal design and truck-mounted testing of aerodynamic performance for the propeller of high altitude airship

Considering the overall requirements of the propeller of a high altitude airship, the propeller was optimized and a truck-mounted testing of aerodynamic performance was carried out. The blade element momentum theory was used to calculate the aerodynamic performance of propeller and verify it by wind tunnel test. By combining blade element momentum theory with genetic algorithm, the chord and twist angle of the original propeller can be optimized, making the propeller more efficient and lightweight, and the aerodynamic efficiency at design point of propeller increased by 2.3%. Then, a truck-mounted testing system was proposed and applied into the acquired propeller test in different altitudes and atmosphere parameters, and the aerodynamic performance of optimized propeller at different conditions was acquired. The results obtained from the truck-mounted testing for the propeller of high altitude airship show that the higher altitude means the smaller thrust and torque with the same rotational speed and free flow. The average relative error of the thrust and torque of the full-scale propeller are 2.8% and 9.2% at altitude of 3.6km. Thus, the test results are in good agreement with the numerical simulation, verifying the accuracy of the system.