the current study presents the results of the aerodynamic noise prediction of the flow field around a naca 0012 airfoil at a chord-based reynolds number of 100,000 and at 8.4 degree angle of attack. an incompressible large eddy simulation (les) turbulence model is applied to obtain the instantaneous turbulent flow field. the noise prediction is performed by the ffowcs williams and hawkings (fw-...

In order to reduce aerodynamic noise radiated from the turbulent wake of bluff bodies, vorticity structures and flow field around a rotating circular cylinder at Reynolds numbers between 102 and 104 were numerically investigated. Vorticity structures and resultant aerodynamic noise is strongly dependant on the velocity ratio, which is defined as flow velocity over rotational speed to the cylind...

Reduction of the aerodynamic noise generated by pantographs is a matter of great important for further speedup of the high speed trains. In general, pantographs are composed of some kind of bluff bodies. Therefore, the method to reduc e the aerodynamic noise generated by bluff bodies is demanded. In this paper, we will present the noise reduction effect of cylinder by equipping intermittent hol...

Purpose – The purpose of this paper is to estimate aerodynamic parameters accurately from flight data in the presence of unknown noise characteristics. Design/methodology/approach – The introduced adaptive filter scheme is composed of two parallel UKFs. At every time-step, the master UKF estimates the states and parameters using the noise covariance obtained by the slave UKF, while the slave UK...

On the basis of small axial fan with five blades, 6 types of small axial flow fans with different chord lengths splitter blades were designed. Numerical simulation of 6 fan models with splitter blades and prototype fan were done by using Fluent. Based on the obtained simulation results, internal flow characteristics and aerodynamic noise were analyzed and compared. It indicates that: splitter b...