End-Wall and Profile Losses in a Low-Speed Axial Flow Compressor Rotor

Abstract

The blade-to-blade variation of relative stagnation pressure losses in the tip region inside the rotor of a single-stage, axial-flow compressor is presented and interpreted in this paper. The losses are measured at two flow coefficients (one at the design point and the other at the near peak pressure rise point) to discern the effect of blade loading on the end-wall losses. The tip clearance losses are found to increase with an increase in the pressure rise coefficient. The losses away from the tip region and near the hub regions are measured downstream. The losses are integrated and interpreted in this paper.

Unsteady Viscous Flow in a High Speed Core Compressor

“…The vortical activity toward the hub is thought to indicate separation of the suction surface/endwall boundary layer due to low momentum fluid in the endwall boundary layer being swept into the endwall-corner under the action of the cross passage pressure gradient. The extent of these features bears close similarity to high loss regions measured behind low-speed rotors by Dring et al (1982), Lakshminarayana et al (1985) and by Dong et al (1987). The measurements shown in Fig 8 indicate that these features are offset slightly to the pressure surface side of the 2D wake flow; this is probably a consequence of different amounts of underturning within the endwall-corner separation relative to that in the 2D wake and the fact that the measurements were taken some way downstream of the rotor trailing edge (see Table 1) .…”

“…A number of workers have undertaken detailed measurements of the flow in axial compressors. Ravindranath & Lakshminarayana (1980) and Lakshminarayana & Govindan (1981) investigated the characteristics of blade wake development while Dring et al (1983), Lakshminarayana et al (1985) and Dong et al (1987) extended these studies to include secondary flow development in the hub and tip regions. Further, Wagner et al (1978) and Zeirke & Okiishi (1982) investigated the effects of bladerow interaction.…”

An Improved Streamline Curvature Approach for Off-Design Analysis of Transonic Axial Compression Systems

“…A well-known feature not included in the ϖ tip determination is the increase in tip loss with loading, demonstrated in Figure 3 -4, taken from Lakshminarayana, et al, 1985. The figure shows the loss contours very near the trailing edge of a low-speed axial compressor rotor at a design (ϕ = 0.56) and a highly loaded (ϕ = 0.5) condition.…”

“…The effects of spanwise mixing are clearly shown. Note that the loss is approximately doubled at the highly loaded condition, (Lakshminarayana, et al, 1985) A simple approach was taken to include the effects of increased loading (turning) on tip losses. As indicated in Equation (3-3), a parabolic increase with incidence angle was used as a modifier to the original tip loss model, Equation (3-2a):…”

“…The weekly luncheons, occasional "turoboguys' nite out," and other get-togethers provided welcome relief from academic woes. (Konig, et al, 1996) .... (Bloch, et al, 1999).......... (Billet, et al, 1988) (Hah, et al, 1998) (Miller, et al, 1961)....... Figure 3 -4 Contours of tip relative total pressure loss coefficient near rotor trailing edge (Lakshminarayana, et al, 1985). (NASA SP-36, 1965) ............................................................................................................…”