A transport model for the deterministic stresses associated with turbomachinery blade row interactions |
Posted on:2000-11-22 | Degree:Ph.D | Type:Dissertation |
University:Case Western Reserve University | Candidate:van de Wall, Allan George | Full Text:PDF |
GTID:1462390014464839 | Subject:Engineering |
Abstract/Summary: | |
The unsteady process resulting from the interaction of upstream vortical structures with a downstream blade row in turbomachines can have a significant impact on the machine efficiency. A transport model assuming incompressible flow and using linear theory was developed to take this process into account in the computation of time-average multistage turbomachinery flows. The upstream vortical structures are transported by the mean flow of the downstream blade row, redistributing the time-average unsteady kinetic energy (Uke ) associated with the incoming disturbance.; The model was applied to compressor and turbine geometry. For compressors, the Uke associated with upstream 2-D wakes and 3-D tip clearance flows is reduced as a result of the interaction with a downstream blade row. This reduction results from inviscid effects as well as viscous effects and reduces the loss associated with the upstream disturbance. Any disturbance passing through a compressor blade row results in a smaller loss than if the disturbance was mixed-out prior to entering the blade row.; For turbines, the Uke associated with upstream 2-D wakes and 3-D tip clearance flows are significantly amplified by inviscid effects as a result of the interaction with a downstream turbine blade row. Viscous effects act to reduce the amplification of the Uke by inviscid effects but results in a substantial loss. Any disturbance passing through a turbine blade row results in a larger loss than if the disturbance was mixedout prior to entering the blade row. |
Keywords/Search Tags: | Blade row, Associated with upstream 2-D wakes, 3-D tip clearance flows, Interaction, Upstream vortical structures, Transport model, 2-D wakes and 3-D tip, Disturbance |
|
Related items |