Numerical Analysis of a Heater with Conjugate Heat Transfer

2012 ◽  
Vol 629 ◽  
pp. 711-715 ◽  
Author(s):  
Y.G. Bai ◽  
Y.G. Zhang ◽  
Y.F. Liu ◽  
K. Yang ◽  
X.W. Gao
Keyword(s):  
Heat Transfer ◽  
Finite Element Method ◽  
Heat Flux ◽  
Thermal Equilibrium ◽  
Conjugate Heat Transfer ◽  
Dynamic Method ◽  
Fluid Dynamic ◽  
Regenerative Cooling ◽  
Interfacial Heat Flux ◽  
Engine Coolant

This paper focuses on the influence of the conjugative heat transfer in a regenerative cooling structure. With proper numerical modelling by both finite element method and computational fluid dynamic method, the distribution of the temperature in the solid and coolant, the interfacial heat flux, and the stress state and the deformation of this cooling structure are obtained. These results show that the thermal equilibrium of the cooling structure can be achieved in a given flow condition. The present numerical method has significant benefits to solve the heat transfer between engine coolant and solid components.

scholarly journals A Parametrical Study on Convective Heat Transfer between High-Temperature Gas and Regenerative Cooling Panel

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1784
Author(s):  
Jiangyu Hu ◽  
Ning Wang ◽  
Jin Zhou ◽  
Yu Pan
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
High Temperature ◽  
Thermal Protection ◽  
Flow Direction ◽  
Heated Surface ◽  
Heat Transfer Process ◽  
Cocurrent Flow ◽  
Regenerative Cooling ◽  
High Temperature Gas

Thermal protection is still one of the key challenges for successful scramjet operations. In this study, the three-dimensional coupled heat transfer between high-temperature gas and regenerative cooling panel with kerosene of supercritical pressure flowing in the cooling channels was numerically investigated to reveal the fundamental characteristics of regenerative cooling as well as its influencing factors. The SST k-ω turbulence model with low-Reynolds-number correction provided by the pressure-based solver of Fluent 19.2 is adopted for simulation. It was found that the heat flux of the gas heated surface is in the order of 106 W/m2, and it declines along the flow direction of gas due to the development of boundary layer. Compared with cocurrent flow, the temperature peak of the gas heated surface in counter flow is much higher. The temperature and heat flux of the gas heated surface both rises with the static pressure and total temperature of gas. The heat flux of the gas heated surface increases with the mass flow rate of kerosene, and it hardly changes with the pressure of kerosene. Results herein could help to understand the real heat transfer process of regenerative cooling and guide the design of thermal protection systems.

Comparison of 3D Unsteady Transient Conjugate Heat Transfer Analysis on a High Pressure Cooled Turbine Stage With Experimental Data

2017 ◽  
Author(s):  
Jong-Shang Liu ◽  
Mark C. Morris ◽  
Malak F. Malak ◽  
Randall M. Mathison ◽  
Michael G. Dunn
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Heat Flux ◽  
High Pressure ◽  
High Temperature ◽  
Gas Turbine ◽  
Conjugate Heat Transfer ◽  
Turbine Rotor ◽  
Turbine Stage ◽  
Cooling Flow

In order to have higher power to weight ratio and higher efficiency gas turbine engines, turbine inlet temperatures continue to rise. State-of-the-art turbine inlet temperatures now exceed the turbine rotor material capability. Accordingly, one of the best methods to protect turbine airfoil surfaces is to use film cooling on the airfoil external surfaces. In general, sizable amounts of expensive cooling flow delivered from the core compressor are used to cool the high temperature surfaces. That sizable cooling flow, on the order of 20% of the compressor core flow, adversely impacts the overall engine performance and hence the engine power density. With better understanding of the cooling flow and accurate prediction of the heat transfer distribution on airfoil surfaces, heat transfer designers can have a more efficient design to reduce the cooling flow needed for high temperature components and improve turbine efficiency. This in turn lowers the overall specific fuel consumption (SFC) for the engine. Accurate prediction of rotor metal temperature is also critical for calculations of cyclic thermal stress, oxidation, and component life. The utilization of three-dimensional computational fluid dynamics (3D CFD) codes for turbomachinery aerodynamic design and analysis is now a routine practice in the gas turbine industry. The accurate heat-transfer and metal-temperature prediction capability of any CFD code, however, remains challenging. This difficulty is primarily due to the complex flow environment of the high-pressure turbine, which features high speed rotating flow, coupling of internal and external unsteady flows, and film-cooled, heat transfer enhancement schemes. In this study, conjugate heat transfer (CHT) simulations are performed on a high-pressure cooled turbine stage, and the heat flux results at mid span are compared to experimental data obtained at The Ohio State University Gas Turbine Laboratory (OSUGTL). Due to the large difference in time scales between fluid and solid, the fluid domain is simulated as steady state while the solid domain is simulated as transient in CHT simulation. This paper compares the unsteady and transient results of the heat flux on a high-pressure cooled turbine rotor with measurements obtained at OSUGTL.

Conjugate Heat Transfer Analysis for Gas Turbine Cooled Stator

2012 ◽  
Author(s):  
Kuo-San Ho ◽  
Christopher Urwiller ◽  
S. Murthy Konan ◽  
Jong S. Liu ◽  
Bruno Aguilar
Keyword(s):  
Heat Transfer ◽  
Gas Turbine ◽  
Test Data ◽  
Conjugate Heat Transfer ◽  
Fluid Dynamic ◽  
Thermal Analyses ◽  
Convection Heat Transfer ◽  
Heat Transfer Analysis ◽  
Engine Test ◽  
Adiabatic Wall

This paper explores the conjugate heat transfer (CHT) numerical simulation approach to calculate the metal temperature for the gas turbine cooled stator. ANSYS CFX12.1 code was selected to be the computational fluid dynamic (CFD) tool to perform the CHT simulation. The 2-equation RNG k-ε turbulence model with scalable modified wall function was employed. A full engine test with thermocouple measurement was performed and used to validate the CHT results. Metal temperatures calculated with the CHT model were compared to engine test data. The results demonstrated good agreement between test data and airfoil metal temperatures and cooling flow temperatures using the CHT model. However, the CHT calculations in the outer end wall had a discrepancy compared to the measured temperatures, which was due to the fact that the CHT model assumed an adiabatic wall as a boundary condition. This paper presents a process to calculate convection heat transfer coefficient (HTC) for cooling passages and airfoil surfaces using CHT results. This process is possible because local wall heat flux and fluid temperatures are known. This approach assists in calibrating an in-house conduction thermal model for steady state and transient thermal analyses.

Comparison of Predictions From Conjugate Heat Transfer Analysis of a Film-Cooled Turbine Vane to Experimental Data

2013 ◽  
Author(s):  
Ron-Ho Ni ◽  
William Humber ◽  
George Fan ◽  
John P. Clark ◽  
Richard J. Anthony ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Conjugate Heat Transfer ◽  
Metal Temperature ◽  
Heat Transfer Analysis ◽  
Barrier Coating ◽  
Turbine Vane ◽  
Flux Measurements ◽  
Surface Metal ◽  
Air Force Research Laboratory

Conjugate heat transfer analysis was conducted on a 648 hole film cooled turbine vane using Code Leo and compared to experimental results obtained at the Air Force Research Laboratory Turbine Research Facility. An unstructured mesh with fully resolved film holes for both fluid and solid domains was used to conduct the conjugate heat transfer simulation on a desktop PC with eight cores. Initial heat flux and surface metal temperature predictions showed reasonable agreement with heat flux measurements but under prediction of surface metal temperature values. Root cause analysis was performed, leading to two refinements. First, a thermal barrier coating layer was introduced into the analysis to account for the insulating properties of the Kapton layer used for the heat flux gauges. Second, inlet boundary conditions were updated to more accurately reflect rig measurement conditions. The resulting surface metal temperature predictions showed excellent agreement relative to measured results (+/− 5 degrees K).

Integrated Fluxes in Magneto-Hydrodynamic Mixed Convection in a Cavity Sustained by Conjugate Heat Transfer

2019 ◽  
Vol 141 (11) ◽  
Author(s):  
Orkodip Mookherjee ◽  
Shantanu Pramanik
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Heat Flux ◽  
Kinetic Energy ◽  
Mixed Convection ◽  
Conjugate Heat Transfer ◽  
Numerical Study ◽  
Horizontal Magnetic Field ◽  
Flow And Heat Transfer ◽  
Stationary Interface

Abstract A numerical study of magneto-hydrodynamic mixed convection in a cavity has been conducted to investigate the influence of magnetic field on integrated flux of thermal energy, linear momentum, and kinetic energy. Shear force through lid motion establishes the forced convection effect and buoyancy force due to differential heating of the moving lid and the stationary interface ensures the natural convection phenomenon. Additionally, conduction through the solid slab with prescribed temperature at the outer surface attached to the cavity induces conjugate heat transfer. Further, the top and bottom walls throughout the domain are kept insulated and a uniform horizontal magnetic field is applied on the interface toward left. Fluid flow and heat transfer characteristics are examined for a range of Hartmann number (Ha): 0, 10, 50, and 120 at fixed values of Reynolds number, Grashof number, and Prandtl number of 300, 9 × 104 and 0.71, respectively. The result shows that the transport of heat in the near wall regions of the fluid domain is primarily governed by diffusion, whereas advection appears stronger in the central region of the cavity. Increase in magnetic field strength from Ha = 0 to 120 gradually suppresses the recirculating structure of the flow signifying a reduction in advective strength as depicted by the decrease in the value of total integrated heat flux from 25.15×10-3 to 6.0×10-3. The reduction in heat flux, momentum fluxes, and kinetic energy fluxes with increase in magnetic field has been well correlated in the range of 0≤Ha≤120.

Streamline upwind finite element method for conjugate heat transfer problems

2005 ◽  
Vol 21 (5) ◽  
pp. 436-443 ◽  
Author(s):  
Niphon Wansophark ◽  
Atipong Malatip ◽  
Pramote Dechaumphai
Keyword(s):  
Heat Transfer ◽  
Finite Element Method ◽  
Finite Element ◽  
Conjugate Heat Transfer ◽  
Transfer Problems ◽  
Element Method

An Investigation of Conjugate Heat Transfer Simulations Based on Discontinuous Galerkin Methods on Unstructured Grids

2013 ◽  
Author(s):  
Zengrong Hao ◽  
Xiaodong Ren ◽  
Yin Song ◽  
Chunwei Gu
Keyword(s):  
Heat Transfer ◽  
Discontinuous Galerkin ◽  
Data Exchange ◽  
Conjugate Heat Transfer ◽  
Unstructured Grids ◽  
Fluid Dynamic ◽  
Exchange Process ◽  
Turbulence Models ◽  
Unified Algorithm ◽  
Dg Methods

A framework for the simulations of conjugate heat transfer (CHT) problems using discontinuous Galerkin (DG) methods on unstructured grids is presented. The compressible fluid dynamic equations and solid heat conduction equations are discretized into the explicit DG formulations simultaneously. The Bassi-Rebay method is used in the gradients computation inside both fluid and solid domains. Fully coupled strategy based on the data exchange process via the numerical flux of interface quadrature points is devised. Various turbulence models and the local-variable-based transition model γ -Reθ are assimilated into the unified algorithm framework. The feasibility of the methodology is validated by some test cases. The work can be viewed as a primary attempt towards further investigations of DG and other high-accuracy methods applications in the engineering CHT problems.

Large Eddy Simulation of Conjugate Heat Transfer Around a Multi-Perforated Plate With Deviation

2016 ◽  
Author(s):  
Dorian Lahbib ◽  
Antoine Dauptain ◽  
Florent Duchaine ◽  
Franck Nicoud
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Large Eddy Simulation ◽  
Conjugate Heat Transfer ◽  
Pressure Ratio ◽  
Perforated Plate ◽  
Inlet Temperature ◽  
Plate Temperature ◽  
Eddy Simulation ◽  
Large Eddy

To improve gas turbine efficiency, engine manufacturers increase both the overall compressor pressure ratio and the turbine inlet temperature, resulting into a higher thermal load of the combustion chamber walls. Cooling systems such as multi-perforated plates are in this context good candidates to lower the thermal constraints on the liners. Such technological devices consist in introducing, through submillimetric holes, a cold air flow into the boundary layer of the chamber wall. Though commonly used in industrial applications, perforations with an angle of deviation, i.e. not aligned with the main flow, have not been studied in most experimental and numerical studies. The deviation angle impacts the liner temperature by modifying the flow structure around the plate. Conjugate heat transfer computations coupling Large Eddy Simulation and heat conduction are performed on streamwise and 45 angled configurations composed of 12 rows at an operating point representative of helicopter combustors to analyze the effect of the deviation. The flow organization around the plate is modified, yielding different heat flux distribution and plate temperature. The major differences are observed within the perforations where the heat flux coefficient increases up to 54% in the configuration with deviation.

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