Incorporating irregular nonlinear waves in simulation of dropped cylindrical objects

Abstract

This study investigates the use of second-order irregular waves for estimating loads on dropped objects. The theory for the irregular nonlinear wave model is integrated into a motion prediction model to simulate the falling process of a dropped cylinder under irregular waves. Through frequency analysis, the simulated irregular waves are transformed into wave spectrum by fast Fourier transform and compared with the target wave spectrum. A good agreement between simulated wave spectrum and target wave spectrum indicates the validity of the irregular nonlinear wave model. The effects of cylinder mass density, wave amplitude and initial wave phase on the trajectory and terminal conditions of dropped cylindrical object are systematically investigated, and the simulated results are compared with those induced by regular waves.

Hybrid Numerical Simulation of Jet Blast Distance of a Departing Aircraft

“…Although the RANS method requires the minimal computational effort, the pulsating motion details are smoothed out by homogenizing the turbulent fluctuations [12]. erefore, it is impossible to accurately simulate the growth rate of the shear layer and turbulence details such as the inviscid velocity of the jet, which is not affected by the shear layer [13][14][15]. Scholars at home and abroad have used the LES (large eddy simulation) method to carry out numerical simulations on jet blast.…”