Study on the temporal and spatial characteristics of high-speed turbulent flow field and its optical transmission effects

2011 ◽  
Author(s):  
Cheng Chen ◽  
Jindong Fei ◽  
Shihe Yi ◽  
Wenzhuo Tang
Keyword(s):  
Flow Field ◽  
Turbulent Flow ◽  
High Speed ◽  
Optical Transmission ◽  
Spatial Characteristics ◽  
Turbulent Flow Field ◽  
Temporal And Spatial ◽  
Temporal And Spatial Characteristics

Study on the Turbulent Injury Principle of Blood in the High-Speed Spiral Blood Pump

2011 ◽  
Vol 393-395 ◽  
pp. 992-995
Author(s):  
Zhong Yun ◽  
Chuang Xiang ◽  
Xiao Yan Tang ◽  
Fen Shi
Keyword(s):  
Shear Stress ◽  
Flow Field ◽  
Blood Cell ◽  
Turbulent Flow ◽  
Red Blood Cell ◽  
Blood Cells ◽  
High Speed ◽  
Internal Flow ◽  
Blood Pump ◽  
Turbulent Flow Field

The strongly swirling turbulent flow in the internal flow field of a high-speed spiral blood pump(HSBP), is one of important factors leading to the fragmentation of the red blood cell(RBC) and the hemolysis. The study on the turbulent injure principle of blood in the HSBP is carried out by using the theory of waterpower rotated flow field and the hemorheology. The numerical equation of the strongly swirling turbulent flow field is proposed. The largest stable diameter of red blood cells in the turbulent flow field is analyzed. The determinant gist on the red blood cell turbulent fragmentation is obtained. The results indicate that in the HSMP, when turbulent flow is more powerful, shear stress is weaker, the vortex mass with energy in flow field may cause serious turbulent fragmentation because of the diameter which is smaller than the RBC’s. The RBC’s turbulent breakage will occur when the Weber value is larger than 12.

The Criterion of Red Blood Cell’s Fragmentation and the Turbulent Flow Field Simulation Analysis in the High-Speed Spiral Blood Pump

2011 ◽  
Vol 422 ◽  
pp. 767-770
Author(s):  
Zhong Yun ◽  
Xiao Yan Tang ◽  
Chuang Xiang ◽  
Fen Shi
Keyword(s):  
Flow Field ◽  
Turbulent Flow ◽  
High Speed ◽  
Cfd Simulation ◽  
Simulation Analysis ◽  
Internal Flow ◽  
Blood Pump ◽  
Important Index ◽  
Simulation Results ◽  
Turbulent Flow Field

For a blood pump, the injury to blood is a very important index of its performance. The strongly swirling turbulent flow in the internal flow field of a high-speed spiral blood pump(HSBP), is one of important factors leading to the fragmentation of the red blood cell(RBC) and the hemolysis. The study on the turbulent injure principle of blood in the HSBP is carried out by using the theory of the turbulent flow field and the hemorheology. The determinant gist on RBC turbulent fragmentation is obtained. The turbulent flow in the designed HSBP have been simulated and analyzed by using the multiphase suspend body CFD simulation technology. The simulation results indicate that the turbulence in the designed HSBP can meet the requirements of blood physiology.

Numerical simulations and analysis of the turbulent flow field in a practical gas turbine engine combustor

2021 ◽  
pp. 095765092110632
Author(s):  
Veeraraghava R Hasti ◽  
Prithwish Kundu ◽  
Sibendu Som ◽  
Jay P Gore
Keyword(s):  
Flow Field ◽  
Turbulent Flow ◽  
Numerical Simulations ◽  
Gas Turbine ◽  
Adaptive Mesh Refinement ◽  
Three Dimensional ◽  
Adaptive Mesh ◽  
Turbulent Structures ◽  
Cut Cell ◽  
Turbulent Flow Field

The turbulent flow field in a practical gas turbine combustor is very complex because of the interactions between various flows resulting from components like multiple types of swirlers, dilution holes, and liner effusion cooling holes. Numerical simulations of flows in such complex combustor configurations are challenging. The challenges result from (a) the complexities of the interfaces between multiple three-dimensional shear layers, (b) the need for proper treatment of a large number of tiny effusion holes with multiple angles, and (c) the requirements for fast turnaround times in support of engineering design optimization. Both the Reynolds averaged Navier–Stokes simulation (RANS) and the large eddy simulation (LES) for the practical combustor geometry are considered. An autonomous meshing using the cut-cell Cartesian method and adaptive mesh refinement (AMR) is demonstrated for the first time to simulate the flow in a practical combustor geometry. The numerical studies include a set of computations of flows under a prescribed pressure drop across the passage of interest and another set of computations with all passages open with a specified total flow rate at the plenum inlet and the pressure at the exit. For both sets, the results of the RANS and the LES flow computations agree with each other and with the corresponding measurements. The results from the high-resolution LES simulations are utilized to gain fundamental insights into the complex turbulent flow field by examining the profiles of the velocity, the vorticity, and the turbulent kinetic energy. The dynamics of the turbulent structures are well captured in the results of the LES simulations.

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