The Effect of Tip Leakage Vortex for Operating Range Enhancement of Centrifugal Compressor

Abstract

Recently, the application of turbochargers is increasing because they are effective in improving fuel consumption of engines. One of the most important turbocharger characteristics is compressor operating range, since it has been used in various driving patterns with the advent of variable geometry turbochargers. Owing to the complicated phenomena, such as rotating stall occurring at low flow rate condition, flow analysis is very difficult and details of flow structure have not been fully understood for a long time since the early 1970s. In this study, two compressors with different operating range width were investigated with experimental and computational flow analysis. In the compressor with narrow operating range, the amplitude of blade passing pressure fluctuation decreases rapidly and rotating stall occurs near surging. On the other hand, in the compressor with wide operating range, the blockage by the tip leakage vortex breakdown play a role in stabilizing the flow field and keeping up a high performance even at low flow rates.

Centrifugal Compressor: The Sound of Surge

“…Higher up in the mid frequency range, a second amplified broadband intensity is observed in between two times the RO and four times the RO frequency, in agreement with Tomita et al 11 as well as Evans and Ward 12 who designates this as the so-called whoosh noise. Whereas Raitor and Neise 7 relates this to tip clearance noise due to leakage between the shroud and the blade tips.…”

“…Galindo et al 9 investigated the influence of the tip clearance size on the acoustic noise generation in a centrifugal compressor, where the variations of the tip clearance have been shown to have insignificant impact on the noise generation at nearsurge operating conditions. Other researchers (Mendonca et al 10 and Tomita et al 11 ) found the occurrence of the narrowband noise at higher frequencies with respect to the rotational speed. Mendonca et al 10 relates a rotating instability with this noise source.…”

Evolution Process of Diffuser Stall in a Centrifugal Compressor With Vaned Diffuser

“…Several researchers have focused on rotating stalls in axial compressors [1][2][3][4]. In addition, several studies have been devoted to the study of rotating stalls in centrifugal compressors [5][6][7][8]. In recent years, there has been a renewed interest in the leading edge vortex (LEV), which is shed from the leading edge of the blade and developing to a rotating stall.…”

Aerodynamic design optimization of a centrifugal compressor impeller based on an artificial neural network and genetic algorithm

“…The investigations to find the mechanisms of map width enhancement of OPT2 are beyond the scope of this paper. The authors have found out the breakdown of the tip leakage vortex plays an important role in stabilizing the unsteadiness of the flow near the stall condition in a separate study (14) .…”