Research Of Compressor Low-energy Fluid Flowing Radially And Stall Mechanism

The flow separation in compressor cascade has very important influence for the internal loss and flow stability,the study of its mechanism and control measures have been challenging research direction in the field of aerodynamics.Corner separation,corner stall and tip leakage flow are the most important of the compressor cascade internal separation structures in a threedimensional space,have the obvious unsteady characteristic and spread across the channel,make a direct impact on compressor performance and stability.In addition,there are secondary flows along the radial rise in the blade channel of the compressor,transport radially a large number of low-energy fluid which have accumulated,making the flow field more complicated.In this paper,based on the radially secondary flow existing in the compressor cascade channel which began from the hub and SST turbulence model.To find several different 1.5 stage compressor for numerical simulation,focus on the influence of different design parameters on the radial flow induced compressor stall reason of the similarities and differences.And the reasons for the stall of the compressor and the mechanism of the stall omen are analyzed in the numerical simulation.Designing compressor stall experiment scheme and verifying its exactness.With the decrease of the massflow,radial flow from rotor gradually rise to the blade tip,and the radial flow from stator is shown as "tornado" type of radial separation vortex structure,the vortex core position moves forward continuously with the decrease of the massflow,then cause a lot of blocking.Changing axial clearance or twist scheme does not change the stall model,shows that tip secondary vortex promotes leakage flow flush out from leading edge,but it changes reason of stall inception,makes transformations of tip vortex its origin and structure with different design parameters.Designing compressor stall experiment scheme in view of the phenomenon of compressor rotating stall,set up experiment platform and analysis characteristics and flow field at stall point below several different rotational speeds,result shows that there is huge low-pressure area near shroud at rotor and stator,which cause a lot of blockage and loss.