Pressure distribution on the frontal disk for turbulent flows in a radial diffuser

The radial diffuser has been used as a basic geometry to study several mechanical devices like thrust bearings, aerosol impactors, artificial heart valves, and refrigeration compressor valves. Experimental results for the pressure distribution on the frontal disk are essential for valve designers because they can provide the force acting on the valve. However, the measurement of this pressure requires a precise procedure, because the flow is highly sensitive to the distance between the frontal disk and the back disk. The main purpose of this work is to provide experimental results for the pressure distribution on the frontal disk of a radial diffuser with a new diameter ratio of 1.5, by using a new technique (an optical sensor) to measure the distance between the disks. A wide range of operation conditions were considered. Pressure distributions were measured for Reynolds number varying from 3,000 to 20,000, considering dimensionless distance between the disks in the range of 0.01-0.09. The results showed very good repeatability with small uncertainties and can be used for validating numerical codes developed to solve the flow through real refrigeration compressor valves.