Basing on a prototype of DCA airfoil and axial displacement overlap of 10% chord,seven kinds of tangential displacements are taken to simulate the flow conditions in tandem cascade with numerical methods to select a b...Basing on a prototype of DCA airfoil and axial displacement overlap of 10% chord,seven kinds of tangential displacements are taken to simulate the flow conditions in tandem cascade with numerical methods to select a better geometry with higher performance.The configuration with tangential displacement b/t=0.83 would gain better flow performance than the others.On this basis,two configurations with tangential displacement b/t=0.67 and 0.83 among several configurations are chosen to take into experimental investigations by using TR-PIV system to capture the flow velocity instantaneously.The configuration with b/t=0.83 is observed a better flow field performance than b/t=0.67.Its injection flow in the gap zone is much stronger,wake zone area of the front and rear blade is smaller and the stream flow is more improved.It shows that the flow performance in experimental investigation is quite in the same trend as the numerical results predict.展开更多
In centrifugal compressors vaneless diffusers can operate over a wide flow range buthave a low pressure recovery coefficient, and vaned diffusers achieve a high pressure recoverybut have a narrow flow range of operati...In centrifugal compressors vaneless diffusers can operate over a wide flow range buthave a low pressure recovery coefficient, and vaned diffusers achieve a high pressure recoverybut have a narrow flow range of operation. After 1981[1], lowsolidity cascade diffusers weredemonstated to have advantages of both above. In order to study the design and analysismethods of LSC diffusers, a Viscous-Inviscid iterative code and a three-dimensional N-Ssolver have been developed respectively The results of both Viscous-Inviscid iterative codeand N-S solver in predicting the flow field of LSC diffusers are agreeable to experimentaldata. The Viscous-Inviscid iterative code is faster and more suitable for original design oroptimization. When detailed flow field analysis is required, the N-S solver has to be adopted.展开更多
文摘Basing on a prototype of DCA airfoil and axial displacement overlap of 10% chord,seven kinds of tangential displacements are taken to simulate the flow conditions in tandem cascade with numerical methods to select a better geometry with higher performance.The configuration with tangential displacement b/t=0.83 would gain better flow performance than the others.On this basis,two configurations with tangential displacement b/t=0.67 and 0.83 among several configurations are chosen to take into experimental investigations by using TR-PIV system to capture the flow velocity instantaneously.The configuration with b/t=0.83 is observed a better flow field performance than b/t=0.67.Its injection flow in the gap zone is much stronger,wake zone area of the front and rear blade is smaller and the stream flow is more improved.It shows that the flow performance in experimental investigation is quite in the same trend as the numerical results predict.
文摘In centrifugal compressors vaneless diffusers can operate over a wide flow range buthave a low pressure recovery coefficient, and vaned diffusers achieve a high pressure recoverybut have a narrow flow range of operation. After 1981[1], lowsolidity cascade diffusers weredemonstated to have advantages of both above. In order to study the design and analysismethods of LSC diffusers, a Viscous-Inviscid iterative code and a three-dimensional N-Ssolver have been developed respectively The results of both Viscous-Inviscid iterative codeand N-S solver in predicting the flow field of LSC diffusers are agreeable to experimentaldata. The Viscous-Inviscid iterative code is faster and more suitable for original design oroptimization. When detailed flow field analysis is required, the N-S solver has to be adopted.
