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 หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Implementation and Validation of k-? Turbulence Model using C++ Open Source Code Software for Thermal Dispersion in Domestic Water Heater) ผู้เขียน: Wisuwat Matchika,  นายชาคริต สุวรรณจำรัส, อาจารย์ สื่อสิ่งพิมพ์:pdf AbstractThe governing equations of the k-? turbulence model were implemented using open source computational fluid dynamic (CFD) codes and open field operation and manipulation (OpenFOAM) software to simulate the thermal dispersion between the water flow and the heater in a domestic water heater. The C++ language was used to develop the CFD codes. The QUICK (Quadratic Upstream Interpolation for Convection Kinetics) scheme was applied with the k-? turbulence model of the thermal dispersion and fluid flow. The SIMPLE (Semi-Implicit Method for Pressure-Linked Equations) algorithm was used to solve the pressure-velocity coupling under turbulence flow. The solutions of the simulations were validated using the experimental results. The transient temperatures at the outlet port of the domestic water heater were obtained using a data acquisition (DAQ) device via K-type thermocouple lines. Twelve cases of the CFD were performed in this study and produced an average error of less than 2.13% when the CFD temperatures were compared with the experimental temperatures. |
หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : The k-? Turbulence Model to Simulate the Two-Phase Flows of Fluids in Flumes using C++ Open Source Code Computational Fluid Dynamic Software) ผู้เขียน:เอกชัย ชัยชนะศิริ, นายชาคริต สุวรรณจำรัส, อาจารย์ สื่อสิ่งพิมพ์:pdf AbstractThe governing equations of two-phase flows based on the k-? turbulence model were developed using open source computational fluid dynamic codes and open field operation and manipulation (OpenFOAM) software to simulate water flows in a flume. The water surface was modeled using the volume of fluid method with a turbulence model. The PISO (pressure implicit with splitting of operator) algorithm was used to solve the pressure-velocity coupling in the two-phase flows. The solutions of the simulations were validated using the experimental results as free surface profiles on the wall of the laboratory flume in transient and steady time periods. The transient time period started from when the water was distributed into the flume until it began to overflow the top of the weirs. The steady time period accounted for the water overflowing the weirs and the surface profiles did not change. It was found that the average error of the surface profiles in the transient and steady time periods obtained from the simulations was 8.94% and 8.06%, respectively. |
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หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Numerical Study on the Strongly Swirling Aerodynamic Field in an Isothermal Vortex Combustor) ผู้เขียน:Smith Eiamsa-ard, Pongjet Promvonge สื่อสิ่งพิมพ์:pdf AbstractThis research presented the application of a mathematical model for simulation of turbulent strongly swirling confined flow in an isothermal vortex combustor. Computations, based on a finite volume method, were carried out by utilizing the standard k-? model and a simplified Algebraic Reynolds Stress Model (ASM) together with three discretization schemes, namely upwind, hybrid and QUICK. The work was performed in order to provide an understanding of physical behaviour of the swirling flow in a cold model vortex combustor. The ASM for steady compressible flows was used to predict the flow and was compared with the k-? turbulence model. The calculated axial and tangential velocity profiles were compared with available measurement data. The mean flow patterns were shown in terms of contour plots. The prediction result showed that the ASM was better than standard k-? model and the ASM together with QUICK results gave good agreement with the measurement data. Moreover, influences of the grid mesh distribution and the value of ? were also studied. |
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