scholarly journals Conjugate Heat Transfer Analysis of the Supercritical CO2 Based Counter Flow Compact 3D Heat Exchangers

2020 ◽  
Author(s):  
Janhavi Chitale ◽  
Abas Abdoli ◽  
George S. Dulikravich ◽  
Adrian S. Sabau ◽  
James B. Black
Keyword(s):  
Heat Transfer ◽  
Heat Exchangers ◽  
Supercritical Co2 ◽  
Conjugate Heat Transfer ◽  
Heat Transfer Analysis ◽  
Counter Flow

Flow Prediction and Conjugate Heat-Transfer Analysis of a Counter Flow Heat-Exchanger with Protruded Fin

2020 ◽  
Vol 12 (3) ◽  
Author(s):  
Manikandan Mohan ◽  
K.C. Udaiyakumar
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Conjugate Heat Transfer ◽  
Flow Analysis ◽  
Heat Transfer Analysis ◽  
Counter Flow ◽  
Tube Heat Exchanger ◽  
Flow Heat ◽  
Optimized Model ◽  
Cfd Method

Voluminous cram has been carried out in this project which is intended to improve the conjugate heat-transfer performance of a heat-exchanger. In this study, CFD method is effectively used to predict the effect of Protruded Fins in heat exchanger, which protrudes inside the tube in addition to the shell side. CFD analysis on Protruded Finned Heat Exchanger (PFHE) is carried out with three different fin configurations like rectangular, triangular and parabolic fins. The baseline model of counter flow shell-tube heat-exchanger is considered with standard dimensions and analyzed initially without fins. Later the numbers of fins are increased to optimize the fin position and counts. The shape of the fins is then modified to find an optimized model with a higher heat-transfer coefficient. Hence, the present conjugate heat-transfer and flow analysis focus on optimizing the number of fins for a heat-exchanger with counter flow along with the shape optimization of fins. The computational values are measured with the net heat exchange between the cold and hot-fluids in terms of temperature difference. Also, the area averaged surface heat transfer co-efficient (h) of the heat exchanger with different fin configurations are plotted and compared.

scholarly journals Fully Coupled Large Eddy Simulation of Conjugate Heat Transfer in a Ribbed Channel with a 0.1 Blockage Ratio

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2096
Author(s):  
Joon Ahn ◽  
Jeong Chul Song ◽  
Joon Sik Lee
Keyword(s):  
Heat Transfer ◽  
Gas Turbine ◽  
Conjugate Heat Transfer ◽  
Heat Transfer Analysis ◽  
Scale Model ◽  
Computational Domain ◽  
Blockage Ratio ◽  
Ribbed Channel ◽  
Large Eddy ◽  
Cooling Passage

Large eddy simulations are performed to analyze the conjugate heat transfer of turbulent flow in a ribbed channel with a heat-conducting solid wall. An immersed boundary method (IBM) is used to determine the effect of heat transfer in the solid region on that in the fluid region in a unitary computational domain. To satisfy the continuity of the heat flux at the solid–fluid interface, effective conductivity is introduced. By applying the IBM, it is possible to fully couple the convection on the fluid side and the conduction inside the solid and use a dynamic subgrid scale model in a Cartesian grid. The blockage ratio (e/H) is set at 0.1, which is typical for gas turbine blades. Through conjugate heat transfer analysis, it is confirmed that the heat transfer peak in front of the rib occurs because of the impinging of the reattached flow and not the influence of the thermal boundary condition. When the rib turbulator acts as a fin, its efficiency and effectiveness are predicted to be 98.9% and 8.32, respectively. When considering conjugate heat transfer, the total heat transfer rate is reduced by 3% compared with that of the isothermal wall. The typical Biot number at the internal cooling passage of a gas turbine is <0.1, and the use of the rib height as the characteristic length better represents the heat transfer of the rib.

scholarly journals Numerical Simulation of Secondary Flow in Gas Turbine Disc Cavities, Including Conjugate Heat Transfer

1996 ◽  
Author(s):  
Y.-H. Ho ◽  
M. M. Athavale ◽  
J. M. Forry ◽  
R. C. Hendricks ◽  
B. M. Steinetz
Keyword(s):  
Heat Transfer ◽  
Secondary Flow ◽  
Conjugate Heat Transfer ◽  
Gas Flow ◽  
Numerical Study ◽  
Labyrinth Seal ◽  
Temperature Fields ◽  
Heat Transfer Analysis ◽  
Flow Rates ◽  
Turbine Disc

A numerical study of the flow and heat transfer in secondary flow elements of the entire inner portion of the turbine section of the Allison T-56/501D engine is presented. The flow simulation included the interstage cavities, rim seals and associated main path flows, while the energy equation also included the solid parts of the turbine disc, rotor supports, and stator supports. Solutions of the energy equations in these problems usually face the difficulty in specifications of wall thermal boundary conditions. By solving the entire turbine section this difficulty is thus removed, and realistic thermal conditions are realized on all internal walls. The simulation was performed using SCISEAL, an advanced 2D/3D CFD code for predictions of fluid flows and forces in turbomachinery seals and secondary flow elements. The mass flow rates and gas temperatures at various seal locations were compared with the design data from Allison. Computed gas flow rates and temperatures in the rim and labyrinth seal show a fair 10 good comparison with the design calculations. The conjugate heat transfer analysis indicates temperature gradients in the stationary intercavity walls, as well as the rotating turbine discs. The thermal strains in the stationary wall may lead to altered interstage labyrinth seal clearances and affect the disc cavity flows. The temperature, fields in the turbine discs also may lead to distortions that can alter the rim seal clearances. Such details of the flow and temperature fields are important in designs of the turbine sections to account for possible thermal distortions and their effects on the performance. The simulation shows that the present day CFD codes can provide the means to understand the complex flow field and thereby aid the design process.

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