Computational study of three-dimensional oblique short wave/vortex interaction

1995 ◽  
Author(s):  
Ashish Nedungadi ◽  
Mark Lewis
Keyword(s):  
Computational Study ◽  
Three Dimensional ◽  
Short Wave ◽  
Vortex Interaction

Three-Dimensional Computational Study of Natural Convection in a Non-Uniformly Heated Vertical Open-Ended Channel

2014 ◽  
Author(s):  
Oxana A. Tkachenko ◽  
Svetlana A. Tkachenko ◽  
Victoria Timchenko ◽  
John A. Reizes ◽  
Guan Heng Yeoh ◽  
...  
Keyword(s):  
Natural Convection ◽  
Computational Study ◽  
Three Dimensional

Wake Flow of Single and Multiple Yawed Cylinders

2004 ◽  
Vol 126 (5) ◽  
pp. 861-870 ◽  
Author(s):  
A. Thakur ◽  
X. Liu ◽  
J. S. Marshall
Keyword(s):  
Computational Study ◽  
Three Dimensional ◽  
Side Wall ◽  
Wake Flow ◽  
Upstream Region ◽  
Two Dimensional ◽  
Cylinder Wake ◽  
Dimensional Approximation ◽  
The Face ◽  
Drag And Lift

An experimental and computational study is performed of the wake flow behind a single yawed cylinder and a pair of parallel yawed cylinders placed in tandem. The experiments are performed for a yawed cylinder and a pair of yawed cylinders towed in a tank. Laser-induced fluorescence is used for flow visualization and particle-image velocimetry is used for quantitative velocity and vorticity measurement. Computations are performed using a second-order accurate block-structured finite-volume method with periodic boundary conditions along the cylinder axis. Results are applied to assess the applicability of a quasi-two-dimensional approximation, which assumes that the flow field is the same for any slice of the flow over the cylinder cross section. For a single cylinder, it is found that the cylinder wake vortices approach a quasi-two-dimensional state away from the cylinder upstream end for all cases examined (in which the cylinder yaw angle covers the range 0⩽ϕ⩽60°). Within the upstream region, the vortex orientation is found to be influenced by the tank side-wall boundary condition relative to the cylinder. For the case of two parallel yawed cylinders, vortices shed from the upstream cylinder are found to remain nearly quasi-two-dimensional as they are advected back and reach within about a cylinder diameter from the face of the downstream cylinder. As the vortices advect closer to the cylinder, the vortex cores become highly deformed and wrap around the downstream cylinder face. Three-dimensional perturbations of the upstream vortices are amplified as the vortices impact upon the downstream cylinder, such that during the final stages of vortex impact the quasi-two-dimensional nature of the flow breaks down and the vorticity field for the impacting vortices acquire significant three-dimensional perturbations. Quasi-two-dimensional and fully three-dimensional computational results are compared to assess the accuracy of the quasi-two-dimensional approximation in prediction of drag and lift coefficients of the cylinders.

scholarly journals Crystal Structure and Computational Study on Methyl-3-Aminothiophene-2-Carboxylate

Crystals ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 19 ◽  
Author(s):  
Yaping Tao ◽  
Ligang Han ◽  
Andong Sun ◽  
Kexi Sun ◽  
Qian Zhang ◽  
...  
Keyword(s):  
Crystal Packing ◽  
Computational Study ◽  
Three Dimensional ◽  
X Ray Diffraction ◽  
Dispersion Energy ◽  
Monoclinic Crystal ◽  
Hydrogen Bond Interactions ◽  
Calculation Results ◽  
Reduced Density Gradient ◽  
Reduced Density

Methyl-3-aminothiophene-2-carboxylate (matc) is a key intermediate in organic synthesis, medicine, dyes, and pesticides. Single crystal X-ray diffraction analysis reveals that matc crystallizes in the monoclinic crystal system P21/c space group. Three matc molecules in the symmetric unit are crystallographically different and further linked through the N–H⋯O and N–H⋯N hydrogen bond interactions along with weak C–H⋯S and C–H⋯Cg interactions, which is verified by the three-dimensional Hirshfeld surface, two-dimensional fingerprint plot, and reduced density gradient (RDG) analysis. The interaction energies within crystal packing are visualized through dispersion, electrostatic, and total energies using three-dimensional energy-framework analyses. The dispersion energy dominates in crystal packing. To better understand the properties of matc, electrostatic potential (ESP) and frontier molecular orbitals (FMO) were also calculated and discussed. Experimental and calculation results suggested that amino and carboxyl groups can participate in various inter- and intra-interactions.

Flow Field Unsteadiness in the Tip Region of a Transonic Compressor Rotor

1997 ◽  
Vol 119 (1) ◽  
pp. 122-128 ◽  
Author(s):  
S. L. Puterbaugh ◽  
W. W. Copenhaver
Keyword(s):  
Flow Field ◽  
High Performance ◽  
Three Dimensional ◽  
Navier Stokes ◽  
Vortex Interaction ◽  
Tip Leakage Vortex ◽  
Tip Leakage ◽  
Transonic Compressor ◽  
Compressor Rotor ◽  
Operating Points

An experimental investigation concerning tip flow field unsteadiness was performed for a high-performance, state-of-the-art transonic compressor rotor. Casing-mounted high frequency response pressure transducers were used to indicate both the ensemble averaged and time varying flow structure present in the tip region of the rotor at four different operating points at design speed. The ensemble averaged information revealed the shock structure as it evolved from a dual shock system at open throttle to an attached shock at peak efficiency to a detached orientation at near stall. Steady three-dimensional Navier Stokes analysis reveals the dominant flow structures in the tip region in support of the ensemble averaged measurements. A tip leakage vortex is evident at all operating points as regions of low static pressure and appears in the same location as the vortex found in the numerical solution. An unsteadiness parameter was calculated to quantify the unsteadiness in the tip cascade plane. In general, regions of peak unsteadiness appear near shocks and in the area interpreted as the shock-tip leakage vortex interaction. Local peaks of unsteadiness appear in mid-passage downstream of the shock-vortex interaction. Flow field features not evident in the ensemble averaged data are examined via a Navier-Stokes solution obtained at the near stall operating point.

scholarly journals Numerical Simulation of the Coagulation Dynamics of Blood

2008 ◽  
Vol 9 (2) ◽  
pp. 83-104 ◽  
Author(s):  
T. Bodnár ◽  
A. Sequeira
Keyword(s):  
Blood Coagulation ◽  
Computational Study ◽  
Time Integration ◽  
Three Dimensional ◽  
Circular Cross Section ◽  
Clot Formation ◽  
Diffusion Reaction ◽  
Numerical Code ◽  
Injured Region ◽  
Reaction Equations

The process of platelet activation and blood coagulation is quite complex and not yet completely understood. Recently, a phenomenological meaningful model of blood coagulation and clot formation in flowing blood that extends existing models to integrate biochemical, physiological and rheological factors, has been developed. The aim of this paper is to present results from a computational study of a simplified version of this coupled fluid-biochemistry model. A generalized Newtonian model with shear-thinning viscosity has been adopted to describe the flow of blood. To simulate the biochemical changes and transport of various enzymes, proteins and platelets involved in the coagulation process, a set of coupled advection–diffusion–reaction equations is used. Three-dimensional numerical simulations are carried out for the whole model in a straight vessel with circular cross-section, using a finite volume semi-discretization in space, on structured grids, and a multistage scheme for time integration. Clot formation and growth are investigated in the vicinity of an injured region of the vessel wall. These are preliminary results aimed at showing the validation of the model and of the numerical code.

Three-dimensional computational study in a corrugated pipe inserted system filled with phase change material

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ömer Akbal ◽  
Hakan F. Öztop ◽  
Nidal H. Abu-Hamdeh
Keyword(s):  
Phase Change ◽  
Phase Change Material ◽  
Computational Analysis ◽  
Computational Study ◽  
Three Dimensional ◽  
Simple Algorithm ◽  
Melting Time ◽  
Geometrical Parameters ◽  
Content Type ◽  
Change Material

Purpose The purpose of this paper is to make a three-dimensional computational analysis of melting in corrugated pipe inserted system filled with phase change material (PCM). The system was heated from the inner pipe, and temperature of the outer pipe was lower than that of inner pipe. Different geometrical ratio cases and two different temperature differences were tested for their effect on melting time. Design/methodology/approach A computational analysis through a pipe with corrugated pipe filled with PCM is analyzed. Finite volume method was applied with the SIMPLE algorithm method to solve the governing equations. Findings The results indicate that the geometrical parameters can be used to control the melting time inside the heat exchanger which, in turn, affect the energy efficiency. The fastest melting time is seen in Case 4 at the same temperature difference which is the major observation of the current work. Originality/value Originality of this work is to perform a three-dimensional analysis of melting of PCM in a corrugated pipe inserted pipe.

Aero-Thermal Investigation of a Rib-Roughened Trailing Edge Channel With Crossing-Jets: Part I—Flow Field Analysis

2008 ◽  
Author(s):  
Alessandro Armellini ◽  
Filippo Coletti ◽  
Tony Arts ◽  
Christophe Scholtes
Keyword(s):  
Flow Field ◽  
Computational Study ◽  
Three Dimensional ◽  
Side Wall ◽  
Field Analysis ◽  
Trailing Edge ◽  
Present Contribution ◽  
Numerical Predictions ◽  
Flow Features ◽  
Rib Roughened

The present contribution addresses the aero-thermal experimental and computational study of a trapezoidal cross-section model simulating a trailing edge cooling cavity with one rib-roughened wall. The flow is fed through tilted slots on one side wall and exits through straight slots on the opposite side wall. The flow field aerodynamics is investigated in part I of the paper. The reference Reynolds number is defined at the entrance of the test section and set at 67500 for all the experiments. A qualitative flow model is deduced from surface-streamline flow visualizations. Two-dimensional Particle Image Velocimetry measurements are performed in several planes around mid-span of the channel and recombined to visualize and quantify three-dimensional flow features. The jets issued from the tilted slots are characterized and the jet-rib interaction is analyzed. Attention is drawn to the motion of the flow deflected by the rib-roughened wall and impinging on the opposite smooth wall. The experimental results are compared with the numerical predictions obtained from the finite volume, RANS solver CEDRE.

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