【摘 要】
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Tip leakage flow(TLF)has a large impact on compressor performance and should be accurately predicted by CFD methods.New approaches to turbulence modelling,such as delayed detached eddy simulation(DDES
【机 构】
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National Key Laboratory of Science and Technology on Aero-Engine Aero-Thermodynamics,School of Energ
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Tip leakage flow(TLF)has a large impact on compressor performance and should be accurately predicted by CFD methods.New approaches to turbulence modelling,such as delayed detached eddy simulation(DDES)have been proposed which allow for greater accuracy of the numerical predictions while computational resources can be tremendously reduced.In this paper,the numerical simulation of the rotor in a low-speed large-scale axial compressor based on DDES is performed subject to different operating conditions of different tip gap sizes.The time-averaged and instantaneous results are compared to analyze the unsteadiness in visual at different tip gap sizes.Then,the anisotropy of the TLF is analyzed through Lumley triangle.The anisotropy varies along the tip leakage vortex(TLV).The anisotropy of the small tip gap condition is weak because the flow at this condition is more stable.Last,the velocity fluctuation data along the TLV are transformed to velocity spectra using fast Fourier transformation(FFT)method to discuss the TLV unsteadiness.
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