Design engineers often employ numerical optimization techniques to assist in the evaluation and comparison of new aircraft conngurations. While the use of numerical optimization methods is largely successful, the presence of numerical noise in realistic engineering optimization problems often inhibits the use of many gradient-based optimization techniques. Numerical noise causes inaccurate grad...

Aeroacoustics, the science of noise generation and propagation through airflows, is a relatively young discipline compared to other more classical fields of mechanics. Nevertheless, it has seen tremendous progress since its foundations were laid in the form of the first overall aeroacoustic theory by Lighthill in his pioneering work in 1952. The basic understanding of aerodynamically generated ...

Railways are an environmentally friendly means of transport that offer many advantages for sustainable development. However, noise and vibration remain a major reason for objections to new lines or network expansions. Railways will never be silent but, it is nevertheless important to reduce their noise and vibration as much as possible while not adding unnecessary cost or complication to their ...

This paper presents initial results on the aeroacoustic and aerodynamic effects of morphing trailing-edge flap 30P30N aerofoil, over five deflections (5–25°), at an 8° angle attack a Reynolds number Re=9.2×105. The Ffowcs-Williams–Hawkings acoustic analogy estimates far-field noise, whilst flow field is solved using URANS with four-equation Transition SST model. Aerodynamic simulation data for ...

The research on helicopter rotor aerodynamic noise becomes imperative with the wide use of helicopters in civilian fields. In this study, a signal enhancement method based cyclic Wiener filtering was proposed given cyclostationarity noise. adaptively filtered out by performing group frequency shifts input signal. According to characteristics noise, detection function constructed realize long-di...