Design, Construction and Performance of Spiral Diffuser

Abstract

Diffuser is a device which increases the pressure of the fluid on the expense of kinetic head. These are commonly used in air conditioners, jet engines, gas turbines etc. Diffusers serve several purposes such as to deliver both conditioning and ventilating air and distribute the flow of air in the desired directions etc. In the present work, the performance of spiral diffuser has been analyzed. The objective of the present investigation is to study the flow and pressure recovery characteristics of Spiral shaped curved diffuser. The flow and performance characteristics of this diffuser are very complicated because of the combined effect of geometrical curvature and flow diffusion. They have lower performance as compared to straight wall diffusers but, have an advantage of occupying less space with respect to straight wall diffusers. The experimental investigation of this diffuser has been carried out at different velocities using suitably designed test rig. Spiral-shaped curved diffusers have different area ratio of (1.72, 1.87 and 2) respectively. Spiral diffusers are designed and fabricated with radial increase in the cross-sectional area, distributed normal to the centreline. The graphs in spiral diffusers are plotted between ΔP and x/L.