A Numerical Analysis of Three-Dimensional Compressible Turbulent Flows in Cascades and Ducts

1984 ◽  
pp. 19-30 ◽  
Author(s):  
Y. Shikano ◽  
M. Ikegawa ◽  
S. Nakano
Keyword(s):  
Numerical Analysis ◽  
Turbulent Flows ◽  
Three Dimensional

Three-Dimensional Numerical Analysis of Transient Natural Convection in Rectangular Enclosures

1979 ◽  
Vol 101 (1) ◽  
pp. 114-119 ◽  
Author(s):  
A. M. C. Chan ◽  
S. Banerjee
Keyword(s):  
Porous Media ◽  
Natural Convection ◽  
Numerical Analysis ◽  
Turbulent Flows ◽  
Numerical Technique ◽  
Three Dimensional ◽  
Experimental Results ◽  
Primitive Form ◽  
Conservation Equations ◽  
Practical Utility

A simple numerical technique of considerable practical utility for the solution of transient multidimensional natural convection problems is described. It is based on the solution of the conservation equations in primitive form. The technique can be extended to calculation of natural convection problems in porous media and in turbulent flows where the eddy viscosities and conductivities can be predicted. It has been applied to the solution of several two and three-dimensional natural convection problems. The solutions compare well with the numerical and experimental results published by other investigators.

scholarly journals Numerical analysis of three-dimensional compressible turbulent flows in a turbine stage.

1987 ◽  
Vol 53 (496) ◽  
pp. 3622-3628
Author(s):  
Yoshio SHIKANO ◽  
Masahiro IKEGAWA ◽  
Susumu NAKANO ◽  
Takeshi SAITOH
Keyword(s):  
Numerical Analysis ◽  
Turbulent Flows ◽  
Three Dimensional ◽  
Turbine Stage

PSL—An Economical Approach to the Numerical Analysis of Near-Wall, Elliptic Flow

1984 ◽  
Vol 106 (2) ◽  
pp. 241-242 ◽  
Author(s):  
H. Iacovides ◽  
B. E. Launder
Keyword(s):  
Numerical Analysis ◽  
Numerical Computation ◽  
Turbulent Flows ◽  
Three Dimensional ◽  
Elliptic Flow ◽  
Computational Time ◽  
Three Dimensional Flow ◽  
Fine Grid ◽  
Dimensional Flow ◽  
Grid Analysis

The paper points out that, in the numerical computation of elliptic or three-dimensional turbulent flows, the neglect of pressure-variations across the very thin viscosity affected region near the wall allows a fine-grid analysis of this sublayer without prohibitive penalties in core or computational time. The scheme has been successfully applied to the three-dimensional flow around a U-bend.

Three dimensional numerical analysis of heat transfer during spray quenching of 22MnB5 steel with a single nozzle

2020 ◽  
Author(s):  
Emre Bulut ◽  
Gökhan Sevilgen ◽  
Ferdi Eşiyok ◽  
Ferruh Öztürk ◽  
Tuğçe Turan Abi
Keyword(s):  
Heat Transfer ◽  
Numerical Analysis ◽  
Three Dimensional ◽  
22Mnb5 Steel

scholarly journals Numerical Study of Three-Dimensional Surface Jets Emerging from a Fishway Entrance Slot

Water ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1079
Author(s):  
Lena Mahl ◽  
Patrick Heneka ◽  
Martin Henning ◽  
Roman B. Weichert
Keyword(s):  
Boundary Conditions ◽  
Turbulent Flows ◽  
Numerical Study ◽  
Three Dimensional ◽  
Free Water ◽  
Lateral Wall ◽  
Lateral Spreading ◽  
Propagation Length ◽  
Vertical Slot ◽  
Surface Jets

The efficiency of a fishway is determined by the ability of immigrating fish to follow its attraction flow (i.e., its jet) to locate and enter the fishway entrance. The hydraulic characteristics of fishway entrance jets can be simplified using findings from widely investigated surface jets produced by shaped nozzles. However, the effect of the different boundary conditions of fishway entrance jets (characterized by vertical entrance slots) compared to nozzle jets must be considered. We investigate the downstream propagation of attraction jets from the vertical slot of a fishway entrance into a quiescent tailrace, considering the following boundary conditions not considered for nozzle jets: (1) slot geometry, (2) turbulence characteristics of the approach flow to the slot, and (3) presence of a lateral wall downstream of the slot. We quantify the effect of these boundary conditions using three-dimensional hydrodynamic-numeric flow simulations with DES and RANS turbulence models and a volume-of-fluid method (VoF) to simulate the free water surface. In addition, we compare jet propagation with existing analytical methods for describing jet propagations from nozzles. We show that a turbulent and inhomogeneous approach flow towards a vertical slot reduces the propagation length of the slot jet in the tailrace due to increased lateral spreading compared to that of a jet produced by a shaped nozzle. An additional lateral wall in the tailrace reduces lateral spreading and significantly increases the propagation length. For highly turbulent flows at fishway entrances, the RANS model tends to overestimate the jet propagation compared to the transient DES model.

Optimization of the Navy’s three-dimensional mine impact burial prediction simulation model, Impact35, using high-order numerical methods

2021 ◽  
pp. 154851292110286
Author(s):  
Athanasios Donas ◽  
Ioannis Famelis ◽  
Peter C Chu ◽  
George Galanis
Keyword(s):  
Numerical Analysis ◽  
Numerical Methods ◽  
Prediction Model ◽  
Simulation Model ◽  
Three Dimensional ◽  
Simulation System ◽  
High Order ◽  
Alternative Methodology ◽  
Runge Kutta ◽  
Fifth Order

The aim of this paper is to present an application of high-order numerical analysis methods to a simulation system that models the movement of a cylindrical-shaped object (mine, projectile, etc.) in a marine environment and in general in fluids with important applications in Naval operations. More specifically, an alternative methodology is proposed for the dynamics of the Navy’s three-dimensional mine impact burial prediction model, Impact35/vortex, based on the Dormand–Prince Runge–Kutta fifth-order and the singly diagonally implicit Runge–Kutta fifth-order methods. The main aim is to improve the time efficiency of the system, while keeping the deviation levels of the final results, derived from the standard and the proposed methodology, low.

scholarly journals Air Ventilation Performance of School Classrooms with Respect to the Installation Positions of Return Duct

2021 ◽  
Vol 13 (11) ◽  
pp. 6188
Author(s):  
Sungwan Son ◽  
Choon-Man Jang
Keyword(s):  
Air Quality ◽  
Numerical Analysis ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Three Dimensional ◽  
Cross Infection ◽  
School Students ◽  
Height Range ◽  
Air Ventilation ◽  
Ventilation Performance

For students, who spend most of their time in school classrooms, it is important to maintain indoor air quality (IAQ) to ensure a comfortable and healthy life. Recently, the ventilation performance for indoor air quality in elementary schools has emerged as an important social issue due to the increase in the number of days of continuous high concentrations of particulate matter. Three-dimensional numerical analysis has been introduced to evaluate the indoor airflow according to the installation location of return diffusers. Considering the possibility of the cross-infection of infectious diseases between students due to the direction of airflow in the classroom, the airflow angles of the average respiratory height range of elementary school students, between 1.0 and 1.5 m, are analyzed. Throughout the numerical analysis inside the classroom, it is found that the floor return system reduces the indoor horizontal airflow that causes cross-infection among students by 20% compared to the upper return systems. Air ventilation performance is also analyzed in detail using the results of numerical simulation, including streamlines, temperature and the age of air.

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