Experimental Investigation of a Transonic Aspirated Compressor

Abstract

The experimental investigation of a transonic aspirated stage demonstrating the application of boundary layer aspiration to increase stage work is presented. The stage was designed to produce a pressure ratio of 1.6 at a tip speed of 750ft∕s resulting in a stage work coefficient of 0.88. The primary aspiration requirement for the stage is a bleed fraction 0.5% of the inlet mass flow on the rotor and stator suction surfaces. Additional aspiration totaling 2.8% was also used at shock impingement locations and other locations on the hub and casing walls. Detailed rotor and stator flow field measurements, which include time-accurate and ensemble-averaged data, are presented and compared to three-dimensional viscous computational analyses of the stage. The stage achieved a peak pressure ratio of 1.58 and through-flow efficiency of 90% at the design point. In addition, the stage demonstrated good performance with an aspiration lower than the design requirement, and a significant off-design flow range below that predicted by the computational analysis.

Boundary layer separation control on a highly-loaded, low-solidity compressor cascade

“…The rotor efficiency of the aspirated compressor reached 96% and stator reached 90% when the aspirated mass flow rate was 4.7% of the passage throughflow, approximately 1.0% aspirated through slots on suction surface of the rotor and stator blades, the remainder distributed over the rotor shroud and stator hub [6]. The experimental investigation of this compressor illustrated that through-flow efficiency at the design point achieved 90% and good performance at off-design point achieved [7]. The high pressure aspirated compressor achieved an isentropic efficiency of 86% when the aspirated mass flow rate was 7% of the passage throughflow, approximated 4% on suction surface and 3% on the hub and shroud near shock impingement [8].…”

“…Dennis investigated the effects of active flow separation control on a stator vane and found separation reduced and total pressure loss of 25% were reduced by injection on the suction surface [5]. The research work of MIT Gas Turbine Laboratory on aspirated compressors gained great success [6][7][8][9][10]. They had first designed two single-stage aspirated compressors, one was a transonic aspirated compressor stage, designed to achieve a pressure ratio of 1.6 at a blade speed of 750 ft/sec, the other was a high pressure ratio aspirated compressor stage, designed to achieve a pressure ratio of 3.5 at a blade speed of 1500 ft/sec.…”

Effect of Partial Span Aspiration on the Performance of a Transonic Axial Compressor Rotor: A Numerical Study

“…One of the strategies is modifying the blade with an aspiration slot, which will suck the low energy separated fluid from the suction side of the blade, making the downstream boundary layer thinner. Experimental investigation on a 1.6 pressure ratio transonic axial compressor stage, demonstrating the application of boundary layer aspiration on the rotor and stator suction surfaces, has been reported by Schuler et al [2]. The primary aspiration mass flow rate was 0.5% of the inlet mass flow rate.…”

State-of-Art of Transonic Axial Compressors

“…Fig. 14 shows the sketch of a transonic aspirated stage experimentally tested and numerically investigated to demonstrate the application of boundary layer aspiration for increasing the stage work (Schuler et al, 2005). The stage was designed to produce a pressure ratio of 1.6 at a tip speed of 750 ft/s resulting in a stage work coefficient of 0.88.…”