Spectrum analysis of unsteady cavitation flow around two-dimensional hydrofoil

Based on the RANS equations,RNG k-eturbulent models and homogeneous multi-phase cavitation models are used to simulate the cavitation flow around the two-dimensional hydrofoil.In the case of the constant inlet velocity and cavitation number,the cavitation profiles changing with the attack angle are researched,and the spectrum analysis of the hydrofoil is carried out by the FFT method.The results show that the cavitation profiles are determined by the cavitation number and the angle of attack.If the cavitation number is constant,the cavitation will be more intensive as the angle of attack increases.In the case of foliated cavitation,the lift signal is a low-frequency signal,which will decrease a little with an increase in the attack angle.In the case of clouds cavitation,the lift signal is a medium-high-frequency signal,which will also decrease a little with an increase in the attack angle.From the foliated cavitation to the clouds cavitation,there is a transition in the conversion process,in which the frequency of the lift signal has various characteristics in every channel.