Boundary layers and hypersonic inlet flow fields

1966 ◽  
Author(s):  
W. GALLO ◽  
A. GNOS ◽  
E. LATHAM
Keyword(s):  
Boundary Layers ◽  
Flow Fields ◽  
Inlet Flow ◽  
Hypersonic Inlet

Numerical Simulations of Flow in Cerebral Aneurysms: Comparison of CFD Results and In Vivo MRI Measurements

2008 ◽  
Vol 130 (5) ◽  
Author(s):  
Vitaliy L. Rayz ◽  
Loic Boussel ◽  
Gabriel Acevedo-Bolton ◽  
Alastair J. Martin ◽  
William L. Young ◽  
...  
Keyword(s):  
Flow Fields ◽  
Patient Specific ◽  
Flow Ratio ◽  
Flow Conditions ◽  
Velocity Measurements ◽  
Cfd Simulations ◽  
Specific Flow ◽  
Inlet Flow ◽  
Good Agreement

Computational fluid dynamics (CFD) methods can be used to compute the velocity field in patient-specific vascular geometries for pulsatile physiological flow. Those simulations require geometric and hemodynamic boundary values. The purpose of this study is to demonstrate that CFD models constructed from patient-specific magnetic resonance (MR) angiography and velocimetry data predict flow fields that are in good agreement with in vivo measurements and therefore can provide valuable information for clinicians. The effect of the inlet flow rate conditions on calculated velocity fields was investigated. We assessed the internal consistency of our approach by comparing CFD predictions of the in-plane velocity field to the corresponding in vivo MR velocimetry measurements. Patient-specific surface models of four basilar artery aneurysms were constructed from contrast-enhanced MR angiography data. CFD simulations were carried out in those models using patient-specific flow conditions extracted from MR velocity measurements of flow in the inlet vessels. The simulation results computed for slices through the vasculature of interest were compared with in-plane velocity measurements acquired with phase-contrast MR imaging in vivo. The sensitivity of the flow fields to inlet flow ratio variations was assessed by simulating five different inlet flow scenarios for each of the basilar aneurysm models. In the majority of cases, altering the inlet flow ratio caused major changes in the flow fields predicted in the aneurysm. A good agreement was found between the flow fields measured in vivo using the in-plane MR velocimetry technique and those predicted with CFD simulations. The study serves to demonstrate the consistency and reliability of both MR imaging and numerical modeling methods. The results demonstrate the clinical relevance of computational models and suggest that realistic patient-specific flow conditions are required for numerical simulations of the flow in aneurysmal blood vessels.

Calculation of hypersonic forebody/inlet flow fields

1990 ◽  
Author(s):  
BRADFORD BENNETT ◽  
THOMAS EDWARDS
Keyword(s):  
Flow Fields ◽  
Inlet Flow

Numerical Investigation of unsteady inlet flow fields

1984 ◽  
Author(s):  
T. HSIEH ◽  
A. WARDLAW, JR. ◽  
P. COLLINS ◽  
T. COAKLEY
Keyword(s):  
Numerical Investigation ◽  
Flow Fields ◽  
Inlet Flow

Calculation of inlet flow fields by an implicit technique

1980 ◽  
Author(s):  
S. BIRINGEN ◽  
D. CHAUSSEE ◽  
O. MCMILLAN
Keyword(s):  
Flow Fields ◽  
Inlet Flow

Effects of boundary-layers bleeding on unstart/restart characteristics of hypersonic inlets

2009 ◽  
Vol 113 (1143) ◽  
pp. 319-327 ◽  
Author(s):  
J. Chang ◽  
D. Yu ◽  
W. Bao ◽  
Y. Fan ◽  
Y. Shen
Keyword(s):  
Boundary Layer ◽  
Mach Number ◽  
Boundary Layers ◽  
Total Pressure ◽  
Performance Parameter ◽  
Recovery Coefficient ◽  
Hypersonic Inlet ◽  
Total Pressure Recovery ◽  
Pressure Recovery Coefficient ◽  
Hypersonic Inlets

Abstract A series of mixed-compression hypersonic inlets at different bleeding rates were simulated at different freestream conditions in this paper. The unstart/restart characteristics of hypersonic inlets were analysed and the reasons why the unstart/restart phenomenon is in existence is presented. The unstart/restart characteristics of hypersonic inlets at different bleeding rates were given. The effects of boundary-layer bleeding on the performance parameter (mass-captured coefficient, total-pressure recovery coefficient), starting and restarting Mach number of hypersonic inlets were discussed. In conclusion, boundary-layer bleeding can improve the performance parameter of hypersonic inlets, and can reduce the starting and restarting Mach number, and can broad the operation range of the hypersonic inlet.

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