Energy Gradient Theory of Hydrodynamic Instability

摘要: A new universal theory for flow instability and turbulent transition is proposed in this study. Flow turbulence have been challenging subjects fluid dynamics a century. The critical condition of from experiments differs largely each other Poiseuille flows. This enigma has not clarified so far owing to the difficulty problem. In paper, mechanism presented parallel shear flows energy gradient hydrodynamic proposed. It stated that total transverse direction streamwise main dominate disturbance amplification or decay. Thus, they determine initiation under given initial disturbance. dimensionless parameter K characterizing wall bounded flows, which expressed as ratio gradients two directions. thought should first occur at position Kmax may be most dangerous position. speculation confirmed by Nishioka et al's experimental data. Comparison with data plane pipe indicates idea really valid. found takes place value about 385 both flow, below no will regardless More studies show also valid Couette Taylor-Couette between concentric rotating cylinders. concluded pressure driven configurations.