Prediction of sound pressure level of noise generated from low pressure axial and diagonal flow fans.

Sound pressure level generated by individual portable sound equipment.

INTRODUCTION The use of Personal Digital Audio Players can cause hearing injuries, as the sound is generated directly in the ear canal. It is believed that different types of headphones can cause different amplifications, since they cause changes in the volume and resonance of the ear canal according to their depth. OBJECTIVE This study aimed to determine the sound pressure to which young ind...

End-plate for noise-by-flow control in axial fans

The paper presents a design procedure for anti-vortex endplates that are fitted to tip limited blades of the subsonic axial fans utilised in compact cooling units. The authors study the impact of tip leakage vortex bursting on the performance of the studied class of fans. The vortex breakdown occurs in the swirling flows at a blade’s tip, and is found to be a flow feature associated with the pr...

Computational Prediction of Flow-Generated Sound

This article provides a critical review of computational techniques for flow-noise prediction and the underlying theories. Hybrid approaches, in which the turbulent noise source field is computed and/or modeled separately from the far-field calculation, are afforded particular attention. Numerical methods and modern flow simulation techniques are discussed in terms of their suitability and accu...

A Procedure for Design of the Axial Flow Fans

study the effects of low level laser diode on no production and healing of diabetic and cortisone acetate and normal wounded sd rats

nitric oxide (no) is a small molecule synthesized by most of mammalian cells with diverse biological activities including vasodilatation, host defense and wound healing. impaired wound healing is a common occurrence among diabetics and patients receiving glucocorticoid therapy. on the other hand the application of laser in biomedical area have been increased. thus, the current studies were desi...