Numerical investigation on the effect of a plenum chamber with slot-type casing treatment on the performance of an axial transonic compressor

Abstract

Casing treatment is an effective approach for improving compressor stall margin in axial compressors. A plenum chamber, which connects slots in the circumferential direction, can occasionally be found in slot-type casing treatments. This study investigates the effect of a plenum chamber on the compressor overall performance and stall margin via timeaccurate three-dimensional numerical simulations in a transonic compressor NASA Rotor 37 with a slot-type casing treatment. Four configurations with variable height of plenum chamber are numerically investigated. The unsteady influence of the casing treatment on compressor flow fields is studied using fast Fourier transforms to gain a deeper insight into the function of the plenum chamber. The results indicate that the plenum chamber can reduce the penalty on the compressor's total pressure ratio and adiabatic efficiency induced by the casing treatment effect at the design operating condition. A detuning effect of the plenum chamber is found and proven to be responsible for the decreased compressor performance penalty through a detailed analysis in both the blade passage and casing treatments. The detuning effect dampens the unsteady influence of the casing treatment on the compressor passage flow in terms of shock oscillations and mass flow fluctuations. Thus, the radial scope and degree of the influence induced by the casing treatment is distinctly restrained by the plenum chamber. Slot circulation, which is composed of a bleed flow from the passage into the slots and injection flow from the slots into the passage, is closely related to the stall margin improvement as the casing treatment is implemented. The plenum chamber has no significant impact on the slot circulation and thus on compressor stall margin. However, shallow slots decrease the slot circulation efficiency, which leads to a much lower stall margin enhancement.

Investigation of stall recovery potential in a transonic compressor rotor

“…Most publications on rotating stall have focused on the flow mechanism at the near-stall condition and proposed methods to enlarge the stable flow range. 16–18 Since the “stall hanging” issue occurred on the F100 flow augmented turbofan engine in the mid-1970s, the problem of unrecoverable stall has received wide attention. 19 There are no clear warnings before the occurrence of stall hanging.…”

Flow Control Methods and Their Applicability in Low-Reynolds-Number Centrifugal Compressors—A Review

“…. +0.15% + + [170] 2016 Recirculating slots AC 7.4-8.4% +2% +10% [174] 2016 Recirculating slots AC −2.71% +33.05% [169] 2015 Grooves CC ±0% +2.48% + [192] 2015 Injection nozzle CC 1.5% +37% [193] 2015 Injection nozzle CC 1-12% +30% [175] 2015 Injection tube Turbine blade 323,955 0.3-4% Reduction in total pressure loss [194] 2015 Recirculating slots AC − − +5.7% [195] 2013 Recirculating holes CC −1% −2% +10% [196] 2013 Recirculating slots CC 11% ±0% +20% [197] 2013 Recirculating slots CC −1% +17% [197] 2013 Recirculating slots with vanes CC +2% +4% + [198] 2012 Recirculating slots CC up to 13% ±0% + [198] 2012 Recirculating slots with vanes CC up to 17% ±0% + [173] 2012 Recirculating slots CC + [199] 2011 Recirculating holes CC −2 . .…”