Numerical Investigation of unsteady inlet flow fields

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.

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Calculation of hypersonic forebody/inlet flow fields

10.2514/6.1990-1493 ◽

1990 ◽

Author(s):

BRADFORD BENNETT ◽

THOMAS EDWARDS

Keyword(s):

Flow Fields ◽

Inlet Flow

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Numerical investigation of energy exchange mechanisms between the mean and acoustic flow fields in a simulated rocket combustor

10.2514/6.1990-2310 ◽

1990 ◽

Cited By ~ 1

Author(s):

JOSEPH BAUM

Keyword(s):

Numerical Investigation ◽

Energy Exchange ◽

Flow Fields ◽

Acoustic Flow ◽

The Mean

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Numerical Investigation of Open Cavities with Parallel Insulated Baffles

International Journal of Heat and Technology ◽

10.18280/ijht.380305 ◽

2020 ◽

Vol 38 (3) ◽

pp. 611-621

Author(s):

Gokulavani Palaniappan ◽

Muthtamilselvan Murugan ◽

Qasem M. Al-Mdallal ◽

Bahaaeldin Abdalla ◽

Deog-Hee Doh

Keyword(s):

Numerical Investigation ◽

Stokes Equations ◽

Flow Fields ◽

Navier Stokes ◽

Navier Stokes Equations ◽

Bottom Cavity ◽

Open Cavities ◽

Stream Functions ◽

Vertical Walls ◽

Left And Right

This research reports the outcome of a numerical investigation of convection in ventilation square cavities contains parallel insulated baffles. The left and right walls of the cavity are kept at the high temperature. Whereas the top, bottom cavity walls, parallel baffles are adiabatic. The opening slots are positioned at the top, bottom corners of the hot vertical walls. The governing Navier-Stokes equations are formulated in the form of vorticity- stream functions. The finite difference method is used to find the values of the primitive variables. The effects of baffles size (Sb − 0.25, 0.50, 0.75), 3 various positions of the parallel baffle, Rayleigh number (103 − 106), Reynolds number (30, 300, 600) are discussed with the flow fields, isotherms, and Nusselt number. It is found that the behavior of ventilation cavities does not only depend on the size of the baffles and its positions. It highly depends on the configuration of the ventilation cavity too. Further, the flow fields are restricted by the largest baffles size of Sb = 0.75.

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Numerical investigation to optimize the inlet flow distributor of the intermediate heat exchanger in an HTGR

Nuclear Engineering and Design ◽

10.1016/j.nucengdes.2019.110363 ◽

2020 ◽

Vol 356 ◽

pp. 110363

Author(s):

Qingxiang Hu ◽

Kun Yuan ◽

Wei Peng ◽

Jingdan Cui ◽

Fulei Peng

Keyword(s):

Heat Exchanger ◽

Numerical Investigation ◽

Inlet Flow ◽

Intermediate Heat Exchanger ◽

Flow Distributor

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A Numerical Investigation on the Mixing Behavior of Microcombustors

Volume 1: 23rd Computers and Information in Engineering Conference, Parts A and B ◽

10.1115/detc2003/cie-48245 ◽

2003 ◽

Cited By ~ 1

Author(s):

Ivan A. Anchondo ◽

Ahsan R. Choudhuri

Keyword(s):

Velocity Field ◽

Numerical Investigation ◽

Flow Fields ◽

Air Injection ◽

Geometrical Symmetry ◽

Rich Condition ◽

Mixing Behavior ◽

Methane Mixture ◽

Channel Type

This paper presents a numerical investigation of the mixing of methane and air inside a 5mm high and 40 mm long 2-D channel type microcombustor. Two fuel-air injection schemes are studied at different equivalence ratios. Configuration-I injects methane from an axially located port, whereas configuration-II injects methane from two radially located opposing ports. The velocity field and local methane mixture fractions indicate that the configuration-I provides a superior mixing for lean, stoichiometric and rich equivalence ratios. However, configuration-II yields sufficient mixing only at a fuel rich condition. Also, despite geometrical symmetry of the chamber, flow-fields are highly asymmetric at a lean condition in both configurations.

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