CFD simulation of ozone gas flow for controlling Sitophilus zeamais in rice grains

2020 ◽  
Vol 88 ◽  
pp. 101675
Author(s):  
M.V.A. Silva ◽  
L.R.A. Faroni ◽  
M.A. Martins ◽  
A.H. Sousa ◽  
J.D. Bustos-Vanegas
Keyword(s):  
Gas Flow ◽  
Cfd Simulation ◽  
Sitophilus Zeamais ◽  
Rice Grains

Analysis of a Virtual Prototype First-Stage Rotor Blade Using Integrated Computer-Based Design Tools

2006 ◽  
Author(s):  
Michel Arnal ◽  
Christian Precht ◽  
Thomas Sprunk ◽  
Tobias Danninger ◽  
John Stokes
Keyword(s):  
Heat Transfer ◽  
Gas Flow ◽  
Thermal Loading ◽  
Cfd Simulation ◽  
Three Dimensional ◽  
Life Assessment ◽  
Element Analysis ◽  
Pressure Losses ◽  
Cooling Channels ◽  
Internally Cooled

The present paper outlines a practical methodology for improved virtual prototyping, using as an example, the recently re-engineered, internally-cooled 1st stage blade of a 40 MW industrial gas turbine. Using the full 3-D CAD model of the blade, a CFD simulation that includes the hot gas flow around the blade, conjugate heat transfer from the fluid to the solid at the blade surface, heat conduction through the solid, and the coolant flow in the plenum is performed. The pressure losses through and heat transfer to the cooling channels inside the airfoil are captured with a 1-D code and the 1-D results are linked to the three-dimensional CFD analysis. The resultant three-dimensional temperature distribution through the blade provides the required thermal loading for the subsequent structural finite element analysis. The results of this analysis include the thermo-mechanical stress distribution, which is the basis for blade life assessment.

scholarly journals Thermal Diffusion Performance of a Diffuser by various Guide Vanes configurations

2018 ◽  
Vol 225 ◽  
pp. 03018
Author(s):  
Aja O. Chikere ◽  
Hussain H. Al-Kayiem ◽  
Zainal Ambri A. Karim
Keyword(s):  
Gas Flow ◽  
Cfd Simulation ◽  
Bench Mark ◽  
Ansys Fluent ◽  
Guide Vanes ◽  
Pressure Losses ◽  
Fluent Software ◽  
Thermal Diffuser ◽  
Crosssectional Area ◽  
Large Diffusion

The use of vane-less diffuser with large diffusion angle has shown a setback in the diffusion process of high temperature working fluids. The hot gas flow was characterized as a jet-like flow. This paper presents problem, encountered practically, using a vane-less diffuser with large diffusion angle and how the problem is solved by CFD simulation. The investigated thermal diffuser has a length of 0.3 m, an inlet to outlet crosssectional area ratio of 1:25 and diffusion angle of 115.44o. To resolve the jet-like flow problem and poor distribution of the flow temperature at the diffuser outlet, the study suggested the use of guide-vanes into the diffuser. The study employed CFD simulation by ANSYS-FLUENT software to analyze the flow and thermal process in the diffuser. Three different shapes of guide vanes; block-shaped, oval-shaped and airfoil-shaped were considered in this study and at different vanes diffusion angles, as well as vane-less case, which was adopted as the bench mark case. The simulation results of the velocity, temperature and pressure at the diffuser outlet were compared for all cases. It was found that the guide vanes with symmetrical airfoil profile provided the best performance with most uniform distribution at the outlet of the diffuser. Also, the airfoil-shaped guide vanes resulted in lower pressure losses compared to the block-shaped and oval-shaped guide vanes. According to the analysis results, the diffuser was redesigned to improve the diffusion and temperature distribution across the diffuser outlet.

Experimental Visualization and Numerical Simulation of Liquid-Gas Two-Phase Flows in a Horizontal Pipe

2017 ◽  
Author(s):  
Milad Darzi ◽  
Chanwoo Park
Keyword(s):  
Numerical Simulation ◽  
Gas Flow ◽  
Cfd Simulation ◽  
Glass Tube ◽  
Flow Patterns ◽  
Two Phase Flows ◽  
Two Phase ◽  
Mixture Flow ◽  
Horizontal Pipe ◽  
Flow Rates

This paper presents the results of both visualization experiment and numerical simulation for two-phase (water-air mixture) flows in a horizontal tube. A visualization experimental setup was used to observe various two-phase flow patterns for different flow rates of water/air mixture flow in a glass tube of 12 mm in diameter. Total of 303 experimental data points were compared with Mandhane’s flow map. Most of the data for stratified, plug and slug flows were found to be in good agreement. However, annular flow was observed for relatively lower gas flow rates and also wavy flow occurred at relatively higher liquid flow rates in this experiment. A three-dimensional Computational Fluid Dynamics (CFD) simulation was performed using OpenFOAM employing “interFoam” as the solver to simulate the two-phase flows in horizontal pipe based on Volume-Of-Fluid (VOF) method. The simulated and experimentally observed flow patterns for the same set of superficial velocities shows acceptable similarities for stratified, wavy, plug, slug and annular flows. Also, the computed values of the void fraction and pressure drop for the numerical simulations shows reasonable agreement with well-known correlations in literature.

CFD Simulation of a Coolant Flow and a Heat Transfer in a Pebble Bed Reactor

2008 ◽  
Author(s):  
Wang-Kee In ◽  
Won-Jae Lee ◽  
Yassin A. Hassan
Keyword(s):  
Heat Transfer ◽  
Gas Flow ◽  
Cfd Simulation ◽  
Reverse Flow ◽  
Temperature Drop ◽  
Coolant Flow ◽  
Normal Operation ◽  
Fuel Temperature ◽  
Pebble Bed Reactor ◽  
Detailed Simulation

This CFD study is to simulate a coolant (gas) flow and heat transfer in a PBR core during a normal operation. This study used a pebble array with direct area contacts among the pebbles which is one of the pebbles arrangements for a detailed simulation of PBR core CFD studies. A CFD model is developed to more adequately represent the pebbles randomly stacked in the PBR core. The CFD predictions showed a large variation of the temperature on the pebble surface as well as in the pebble core. The temperature drop in the outer graphite layer is smaller than that in the pebble-core region. This is because the thermal conductivity of graphite is higher than the fuel (UO2 mixture) conductivity in the pebble core. Higher pebble surface temperature is predicted downstream of the pebble contact due to a reverse flow. Multiple vortices are predicted to occur downstream of the spherical pebbles due to a flow separation. The coolant flow structure and fuel temperature in the PBR core appears to largely depend on the in-core distribution of the pebbles.

Numerical Simulation of Real-Gas Flow in a Supersonic Turbine Nozzle Ring

2002 ◽  
Vol 124 (2) ◽  
pp. 395-403 ◽  
Author(s):  
J. Hoffren ◽  
T. Talonpoika ◽  
J. Larjola ◽  
T. Siikonen
Keyword(s):  
Power Plants ◽  
Gas Flow ◽  
Cfd Simulation ◽  
Low Cost ◽  
Design Procedure ◽  
Rankine Cycle ◽  
Simulation Method ◽  
Ideal Gas ◽  
Working Fluid ◽  
Real Gas

In small Rankine cycle power plants, it is advantageous to use organic media as the working fluid. A low-cost single-stage turbine design together with the high molecular weight of the fluid leads to high Mach numbers in the turbine. Turbine efficiency can be improved significantly by using an iterative design procedure based on an accurate CFD simulation of the flow. For this purpose, an existing Navier-Stokes solver is tailored for real gas, because the expansion of an organic fluid cannot be described with ideal gas equations. The proposed simulation method is applied for the calculation of supersonic flow in a turbine stator. The main contribution of the paper is to demonstrate how a typical ideal-gas CFD code can be adapted for real gases in a very general, fast, and robust manner.

CFD Simulation of Propellant Gas Flow Motion in Gas-Operated Systems

2021 ◽  
Author(s):  
Tien Dinh Vu ◽  
Stanislav Prochazka ◽  
Zbynek Krist ◽  
Ban Huu Le ◽  
Bien Van Vo
Keyword(s):  
Gas Flow ◽  
Cfd Simulation ◽  
Flow Motion

Numerical Analysis of Flow Behavior Inside the Blast Furnace

2009 ◽  
Author(s):  
Dong Fu ◽  
Fengguo Tian ◽  
Guoheng Chen ◽  
D. Frank Huang ◽  
Chenn Q. Zhou
Keyword(s):  
Blast Furnace ◽  
Gas Flow ◽  
Cfd Simulation ◽  
Flow Behavior ◽  
Three Dimensional ◽  
Furnace Productivity ◽  
Gas Distribution ◽  
Furnace Shaft ◽  
Parametric Studies ◽  
Flow Through

Gas and burden distributions inside a blast furnace play an important role in optimizing gas utilization versus the furnace productivity and minimizing the CO2 emission in steel industries. In this paper, a mathematical model is presented to describe the burden descent in the blast furnace shaft and gas distribution, with the alternative structure of coke and ore layers being considered. Multi-dimensional Ergun’s equation is solved with considering the turbulent compressible gas flow through the burden column. The porosity of each material will be treated as a function of three dimensional functions which will be determined by the kinetics sub-models accordingly. A detailed investigation of gas flow through the blast furnace will be conducted with the given initial burden profiles along with the effects of redistribution during burden descending. Also, parametric studies will be carried out to analyze the gas distribution cross the blast furnace under different cohesive zone (CZ) shapes, charging rate, and furnace top pressure. A good agreement was obtained between the CFD simulation and published experimental data. Based on the results, the inverse V shape is proved to be the most desirable CZ profile.

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