Role of tip injection in desensitizing the compressor to the tip clearance size

Control of Tip Leakage Flow in Axial Flow Compressor Cascade by Suction on the Blade Tip

“…In the passive flow control methods such as casing treatment (Houghton et al 2012;Sakuma et al 2014;Du et al 2016), blade tip winglet (Han et al 2014(Han et al , 2016 and blade tip modifications (Gourdain et al 2009;Ma et al 2012;Jung et al 2016), the geometrical change always works among the whole operating range and it may lead to a decrease of compressor performance near the design condition. For the active flow control techniques such as plasma actuation (Saddoughi et al 2015;Ashrafi et al 2016), tip injection (Li et al 2015;Grosvenor et al 2015;Khaleghi et al 2016) and casing aspiration (Lee et al 1990;Gmelin et al 2011;Grimshaw et al 2015), however, it can act on the flow fields flexibly either all the time or only when it is needed. As one of the effective active flow control methods, the suction technique attracts the attention from an increasing number of researchers to improve the flow fields in compressors.…”

Examining the effect of annular injection on the parameters of the axial compressor’s stage

“…The injection was performed through two slit openings before the impeller. Article [5] reported an increase in the degree of pressure and performance efficiency achieved at certain parameters of injection. An expression is given to determine performance efficiency coefficient considering the mass of air that is blown out.…”

“…Papers [5,6] present results of research into effect of injection in the impeller on the parameters of stage of an axial compressor. The injection was performed through two slit openings before the impeller.…”

“…Results of studies [1][2][3][4][5][6][7][8][9][10] demonstrated effectiveness of gas-dynamic action on the current in a compressor. At the same time, there are still unresolved problems related to the choice of optimal parameters of the gas-dynamic action.…”

“…However, in studies [5][6][7], the injection is carried out discretely through several slit openings. Under certain conditions, discreteness of injection may lead to an increase in the vortex-formation in a peripheral part of the impeller.…”