EFFECT OF TIP CLEARANCE ON PERFORMANCE OF A CENTRIFUGAL COMPRESSOR

Abstract

The centrifugal compressor is to study the effect o f tip clearance on the performance characteristics and the wall static pressure for a different flow co-efficient. The method of testing the compressor is run at a constant speed at 2000rp m. The tip clearance is varied by using spacers. The volume flow rate is varied with the help of throttling device to conduct the perfor mance test. The performance characteristic of the centrifugal compressor showin g the variation of discharge pressure with volume f low rate is plotted. Obtaining the performance characteristics showing the variati on of discharge pressure with volume flow rate for different tip clearance, viz. �=2.2%, 4%, 6.1% and 7.9%. Measurement of periodic p ressure at various tip clearance viz. �=2.2%, 4%, 6.1% and 7.9%. For each tip clearance pressure measured in radial loca tion of impeller at 6 positions for different flow co efficient values. Five flow coefficients viz., ф =0.40, =0.34 (both above design flow), =0.28 (near design flow), =0.21=0.18 (both below design flow) and four values of non-dimensional tip clearance viz., �=2.2%, 4%, 6.1% and 7.9%, are chosen for experiment al work. The objective of the research work is to measure the periodic variation static pressure on the casing over the rotor at dif ferent values of tip clearance and flow coefficients. With the availability of these data, it is possible to improve the tip clearance flow in centrifugal compressor.