An Unsteady Momentum Source Method and Its Application in Simulation of Hovering Rotor

Abstract

The efficiency and accuracy of numerical simulation on power unit is the key to study the relevant aerodynamic layout with multiple rotating power units. However, the numerical simulation of the power unit using real geometry all faces the problem of low solution efficiency. Taking the rotor hovering state as an example, the real blade was firstly simplified and replaced by a thin mesh disk to establish the effective momentum source method. Then, using fan-shaped mesh region that changes with time to replace real blade and simulate the rotation, the unsteady momentum source method which could get the revolution of tip vortex was proposed. The results show that the momentum source method with the input of accurate blade force distribution can simulate rotor wake better, and the influence that blade geometry acts on wake mainly reflects in the blade force distribution. In addition, the unsteady momentum source method can simulate the revolution of tip vortex, and its consumptions of computing resources and calculation time are only about 1/8 of the unsteady numerical simulation based on the real geometry.

Numerical simulation of hovering flow field and interference characteristics of rotor system

“…Griffiths et al [2] used a free wake model to analyze the disturbance flow field of a dual rotor and the ground effect; Chen et al [3] employed the momentum source method to analyze the tandem rotor aerodynamic characteristics. Guo et al [4] established a non-constant momentum source method to numerically simulate the hovering rotor. Zhu et al [5] studied the non-constant interference between co-axial twin rotor blades under hovering condition.…”