Optimized Shroud Design for Axial Turbine Aerodynamic Performance

2008 ◽  
Vol 130 (3) ◽  
Author(s):  
L. Porreca ◽  
A. I. Kalfas ◽  
R. S. Abhari
Keyword(s):  
Flow Field ◽  
Three Dimensional ◽  
Aerodynamic Performance ◽  
Field Analysis ◽  
Test Cases ◽  
Axial Turbine ◽  
Significant Difference ◽  
Flow Field Analysis ◽  
The Impact ◽  
Partial Shroud

This paper presents a comprehensive study of the effect of shroud design in axial turbine aerodynamics. Experimental measurements and numerical simulations have been conducted on three different test cases with identical blade geometry and tip clearances but different shroud designs. The first and second test cases are representative of a full shroud and a nonaxisymmetric partial shroud geometry while the third test case uses an optimized partial shroud. Partial shrouds are sometimes used in industrial application in order to benefit from the advantage of shrouded configuration, as well as reduce mechanical stress on the blades. However, the optimal compromise between mechanical considerations and aerodynamic performances is still an open issue due to the resulting highly three-dimensional unsteady flow field. Aerodynamic performance is measured in a low-speed axial turbine facility and shows that there are clear differences between the test cases. In addition, steady and time resolved measurements are performed together with computational analysis in order to improve the understanding of the effect of the shroud geometry on the flow field and to quantify the sources of the resultant additional losses. The flow field analysis shows that the effect of the shroud geometry is significant from 60% blade height span to the tip. Tip leakage vortex in the first rotor is originated in the partial shroud test cases while the full shroud case presents only a weak indigenous tip passage vortex. This results in a significant difference in the secondary flow development in the following second stator with associated losses that varies by about 1% in this row. The analysis shows that the modified partial shroud design has improved considerably the aerodynamic efficiency by about 0.6% by keeping almost unchanged the overall weight of this component, and thus blade root stresses. The work, therefore, presents a comprehensive flow field analysis and shows the impact of the shroud geometry in the aerodynamic performance.

Flow Field Analysis and Numerical Simulation for Dynamic Filtration with Rotating Disks

2012 ◽  
Vol 184-185 ◽  
pp. 244-247
Author(s):  
Zhong Bin Liu ◽  
Feng Luo
Keyword(s):  
Flow Field ◽  
Mechanical Stability ◽  
Three Dimensional ◽  
Main Flow ◽  
Field Analysis ◽  
Rotating Disks ◽  
Dynamic Filtration ◽  
Circular Flows ◽  
Flow Field Analysis ◽  
Graphics Software

Dynamic filtration with rotating disks is modeled by three-dimensional graphics software and its flow field is analyzed and numerical simulated by CFD software. The mechanical stability of dynamic filtration with rotating disks in the work process is analyzed by the model of rotating flow. The results show that the farthest end of rotating disks exit the largest flow velocity. There are two circular flows, which can remove the pollutants of rotating disks. The pressure of water is gradually increased as the main flow is near cylinder of the filtration. Simulation results are consistent to the practice, which provides important theoretical basis for improving and optimization of dynamic filtration with rotating disks.

Flow Field Analysis and Numerical Simulation for Pipe with Tee on Fluid-Structure Coupling

2012 ◽  
Vol 503-504 ◽  
pp. 768-771
Author(s):  
Zhong Bin Liu ◽  
Feng Luo ◽  
Tao Zeng ◽  
Hui Wu
Keyword(s):  
Flow Field ◽  
Mechanical Stability ◽  
Three Dimensional ◽  
Main Flow ◽  
Field Analysis ◽  
Fluid Structure ◽  
Coulomb Failure ◽  
Flow Field Analysis ◽  
Simulation Results ◽  
Graphics Software

Y-shaped tee is modeled by three-dimensional graphics software and its flow field is analyzed and numerical simulated by CFD software. The mechanical stability of Y-shaped tee in the work process is analyzed by fluid-structure coupling. The results show that the pressure of water is gradually decreased and the velocity of water is gradually increased as the main flow is near Y-shaped tee; the branch of pipeline exits the largest failure risk by the coulomb failure expression. Simulation results are consistent to the practice, which provides important theoretical basis for improving and optimization of Y-shaped tee.

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