Research On Aerodynamic Interference Between Contra Rotating Propellers

In this paper,based on the APC propeller model,leafy contra-rotating propeller model is constructed,and the numerical analysis of the contra-rotating propeller is performed,finally,the APC contra-rotating propeller and GWS contra-rotating propeller has carried on the wind tunnel experiment.The analysis of the research provides a certain reference for the study of contra-rotating propeller and the interstage flow field.Firstly,the model is built based on the APC propeller model.A numerical simulation was performed for the fixed-pitch eight-leaf APC propeller.The aerodynamic performance of different pitch ratio,flow velocity and the same rotational speed is studied and compared with the calculation results of the single row of eight-blade propellers.Results show that within the scope of the research,when pitch ratio is fixed,a certain mechanical properties of the contra-rotating propeller increase with the increase of flow rate and rotational speed,and efficiency first increased then decreased,the change tendency is same as isolated propeller.Under the same conditions,the mechanical performance is better and the efficiency is higher.Secondly,the numerical simulation of the rotor blades with different number of blades,different interstage spacing and different diameter ratio is carried out.Compared with the performance and flow field changes in different situations,the changes of aerodynamic performance and interlevel flow field at different pitch ratio,flow velocity and the same rotation speed are analyzed.Thirdly,on the basis of the existing small propeller test bench,design and transform a contra-rotating propeller test bench,purchase the measurement system----TFI probe to measure flow field,using the measurement system to confirm wind tunnel flow field is uniform.Finaly,the APC contra-rotating propeller with GWS contra-rotating propeller has carried on the wind tunnel experiment,measured flow field of the axial surface before and after the contra-rotating propeller,analyses the three air velocity component and the change trend of static stress.Results show that the contra-rotating propeller relative to the single blade has a better airflow acceleration effect,in the case of the flow,the flow field of counter rotating blade is more uniform,the more the number of rotating blades,accelerating effect of the airflow is better,more uniform flow field.