Audio-visual interactions in environment assessment

We study the vortex dynamics of a two-dimensional H-rotor wind turbine using a Navier-Stokes solver. The turbulence model with the wall function is used as the turbulence closure. A sliding mesh technique is employed to handle the blade rotation. The vortex-blade interaction is systematically investigated and its influence on the force generation is discussed. Our simulations show that the vortex-blade interaction largely depends on the solidity and tip speed ratio. We further study the impact of solidity on the turbine performance. Our simulations show that the peak torque per blade decreases with the solidity while the peak torque azimuthal angle increases with the solidity. Our simulations also show that the increase in the azimuthal angle is more significant at low tip speed ratios than at high tip speed ratios. The impact of blade thickness is studied. Our simulations show that a thicker airfoil has a higher torque coefficient than a thinner airfoil. However, because for the thinner airfoil its peak ...

Numerical investigation of vortex dynamics in an H-rotor vertical axis wind turbine

Multiobjective design optimization of the performance for the cavity flameholder in supersonic flows

A full engine cycle analysis of a turbofan engine for optimum scheduling of variable guide vanes

Evolution of the flow instabilities in an axial compressor rotor with large tip clearance: An experimental and URANS study

Experimental and numerical study on aeroacoustic sound of axial flow fan in room air conditioner

Numerical prediction of the interaction noise radiated from an axial fan

The aerodynamic and aeroacoustic performances of outdoor unit with two different types of grille have been investigated in present study. Experimental results indicate that the grille sharp will affect the flow rate and increase broadband noise level of outdoor unit. Based on noise generation mechanism and CFD simulation, vortex shedding noise model and inlet turbulence noise model are adopted to predict the broadband noise level of outdoor unit. When vortex shedding noise is concerned, the wake parameters should be calculated at 3 mm downstream of grille to achieve good accuracy. Inlet turbulence noise is generated from the interaction between blade wake and the grille, and plays less important role in present outdoor unit configuration. In comparison with experimental results, it is shown that the broadband noise prediction method could provide reasonable accuracy and the error between prediction and experiment is less than 1 dBA.

Experimental and numerical study on aerodynamic noise of outdoor unit of room air conditioner with different grilles

The effects of an eccentric vortex on the performance of a cross flow fan for air-conditioning is evaluated experimentally and numerically. Based on the two-dimensional computational analysis using commercial CFD software, and experimental measurements, a new design is proposed for the inlet guide vanes. The new design reduces vortex shedding from the fan blades, thereby reducing the size of the eccentric vortex, which results in improved fan efficiency. The new design improves the performance of the cross flow fan marginally by 4.6% at a maximum volumetric flow rate of 10.5 m3 min−1.

Hua Ouyang

Papers

Experimental and numerical study on aeroacoustic sound of axial flow fan in room air conditioner

Numerical prediction of the interaction noise radiated from an axial fan

Experimental and numerical study on aerodynamic noise of outdoor unit of room air conditioner with different grilles

Experimental and numerical investigations on the eccentric vortex of the cross flow fan

Numerical investigation of tip clearance effects on rotating instability of a low-speed compressor