High-performance Computing of Periodic Unsteady Flow Based on Time Spectral Method

AbstractThe engineering application requires the solver of periodic unsteady flows to be of high efficiency and precision. Based on the developing Frequency-Domain methods, a fully implicit version of the Time Spectral Method (TSM) is established, the stability problem that occurs as the sampling number grows is improved. The TSM is extended toSST turbulence model, which improves the numerical accuracy and the ability of simulating complex flows. The periodic unsteady flows over a forced oscillating NACA0015 and Hypersonic Ballistic Shape (HBS) are numerically simulated. The computational results agree well with the experiment data at subsonic and hypersonic regime, validating the application of the TSM solver. Influences of the angle of attack and Ma on dynamic derivatives of the HBS are analyzed. Comparing with the Dual-Time-Step (DTS) method, the relative efficiency of the TSM improves as the Ma number increases. The TSM provides an order of magnitude improvement in computational efficiency over DTS without loss of generality at hypersonic speed regime