Axial compressor

About: Axial compressor is a research topic. Over the lifetime, 12035 publications have been published within this topic receiving 127766 citations.

Numerical and Analytical Study of Fluid Dynamic Forces in Seals and Bearings

Abstract: A numerical model based on a transformed, conservative form of the three dimensional Navier-Stokes equation and an analytical model based on lumped fluid parameters are presented and compared with studies of modeled rotor bearing seal systems. The rotor destabilizing factors are related to the rotative character of the flow field. It is shown that these destabilizing factors can be reduced through a decrease in the fluid average circumferential velocity. However, the rotative character of the flow field is a complex three dimensional system with bifurcated secondary flow patterns that significantly alter the fluid circumferential velocity. By transforming the Navier-Stokes equations to those for a rotating observer and using the numerical code PHOENICS-84 with a nonorthogonal body fitted grid, several numerical experiments were carried out to demonstrate the character of this complex flow field. In general, fluid injection and/or preswirl of the flow field opposing the shaft rotation significantly intensified these secondary recirculation zones and thus reduced the average circumferential velocity; injection or preswirl in the direction of rotation significantly weakened these zones.

Compressor-simulation model with corrections for the level of suction gas superheat

Abstract: A compressor simulation model, based on empirical performance curves from reciprocating compressor manufacturers, is discussed. The compressor model is part of a heat pump simulation model being developed for potential use in reducing the amount of testing required for air-to-air heat pumps by the new rating procedures being implemented by DOE. Corrections to the compressor performance curves (maps) are developed to account for the effect of different superheat (or quality) levels on refrigerant mass flow rate and compressor power; the corrections are in general agreement with the average of the available information from manufacturers of two- to four-ton, R-22, hermetic, reciprocating compressors. Comparisons are made between the compressor model predictions and available data from four heat pump experiments. The comparisons indicate that more experimental data are needed at the lower ambient conditions in the heating mode under conditions of wet suction gas and with lower air temperatures over the compressor shell.

Unsteady Numerical Simulations of Turbulence and Coherent Structures in Axial Flow Near a Narrow Gap

Abstract: Axial flow in a rectangular channel containing a cylindrical rod has been simulated numerically by solving the unsteady Reynolds-averaged Navier-Stokes equations with a Reynolds stress model. The study further documents the formation of quasi-periodic coherent structures in the form of vortex pairs and the important role that they play in transporting fluid across the gap region.