Estimation of the Transient Surface Temperature and Heat Transfer Coefficient of Convective Cooling for Large Slab and Long Cylinder by Using an Inverse Heat Conduction Method

2013 ◽  
Author(s):  
Ramin Soujoudi ◽  
Antonio Campo
Keyword(s):  
Heat Transfer ◽  
Heat Conduction ◽  
Surface Temperature ◽  
Series Solution ◽  
Initial Temperature ◽  
Numerical Solutions ◽  
Thermal Boundary Condition ◽  
Heat Equations ◽  
Inverse Heat Conduction ◽  
Long Cylinder

Inverse heat conduction method is a technique to determine heat flux and surface temperature on an inaccessible surface of wall by measuring the temperature on an accessible boundary. The objective of this paper is to develop a method by which stable prediction of heat transfer on an inaccessible boundary could be obtained without altering the thermal boundary condition that would have existed were sensor not present. In this work, three points backward finite difference applied to the 1-D heat equation for large slab and long cylinder with constant thermophysical properties and uniform initial temperature. The numerical solutions of the heat equations are performed with symbolic Maple software. It is demonstrated that approximate temperature distributions for the three bodies are equivalent to analytical solution using first term series solution. It is also shown that the series solution converge rapidly for long times, and for Fo > 0.2, ony the first term of the series nned to be retained for 2% accuracy.

Inverse Analysis of In-Cylinder Gas-Wall Boundary Conditions: Investigation of a Yittria Stabilized Zirconia Thermal Barrier Coating for Homogeneous Charge Compression Ignition

2016 ◽  
Author(s):  
Ryan O’Donnell ◽  
Tommy Powell ◽  
Mark Hoffman ◽  
Zoran Filipi
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Heat Conduction ◽  
Surface Temperature ◽  
Inverse Analysis ◽  
Fast Response ◽  
Thermal Barrier ◽  
Temperature Profiles ◽  
Inverse Heat Conduction ◽  
Cycle Efficiency

Thermal Barrier Coatings (TBC) applied to in-cylinder surfaces of a Low Temperature Combustion (LTC) engine provide opportunities for enhanced cycle efficiency via two mechanisms: (i) positive impact on thermodynamic cycle efficiency due to combustion/expansion heat loss reduction, and (ii) enhanced combustion efficiency. Heat released during combustion elevates TBC surface temperatures, directly impacting gas-wall heat transfer. Determining the magnitude and phasing of the associated TBC surface temperature swing is critical for correlating coating properties with the measured impact on combustion and efficiency. Although fast-response thermocouples provide a direct measurement of combustion chamber surface temperature in a metal engine, the temperature and heat flux profiles at the TBC-treated gas-wall boundary are difficult to measure directly. Thus, a technique is needed to process the signal measured at the sub-TBC sensor location and infer the corresponding TBC surface temperature profile. This task can be described as an Inverse Heat Conduction Problem (IHCP), and it cannot be solved using the conventional analytic/numeric techniques developed for ‘direct’ heat flux measurements. This paper proposes using an Inverse Heat Conduction solver based on the Sequential Function Specification Method (SFSM) to estimate heat flux and temperature profiles at the wall-gas boundary from measured sub-TBC temperature. The inverse solver is validated ex situ under HCCI like thermal conditions in a custom fabricated radiation chamber where fast-response thermocouples are exposed to a known heat pulse in a controlled environment. The analysis is extended in situ, to evaluate surface conditions in a single-cylinder, gasoline-fueled, HCCI engine. The resulting SFSM-based inverse analysis provides crank angle resolved TBC surface temperature profiles over a host of operational conditions. Such metrics may be correlated with TBC thermophysical properties to determine the impact(s) of material selection on engine performance, emissions, heat transfer, and efficiencies. These efforts will also guide next-generation TBC design.

Nonlinear Inverse Heat Conduction With a Moving Boundary: Heat Flux and Surface Recession Estimation

1999 ◽  
Vol 121 (3) ◽  
pp. 708-711 ◽  
Author(s):  
V. Petrushevsky ◽  
S. Cohen
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Fourier Series ◽  
Heat Conduction ◽  
Moving Boundary ◽  
Heat Conduction Problem ◽  
Inverse Heat Conduction Problem ◽  
Variable Order ◽  
Inverse Heat Conduction ◽  
One Dimensional

A one-dimensional, nonlinear inverse heat conduction problem with surface ablation is considered. In-depth temperature measurements are used to restore the heat flux and the surface recession history. The presented method elaborates a whole domain, parameter estimation approach with the heat flux approximated by Fourier series. Two versions of the method are proposed: with a constant order and with a variable order of the Fourier series. The surface recession is found by a direct heat transfer solution under the estimated heat flux.

scholarly journals Determination of temperature and thermal stresses distribution in power boiler elements with use inverse heat conduction method

2011 ◽  
Vol 32 (3) ◽  
pp. 191-200 ◽  
Author(s):  
sławomir Grądziel
Keyword(s):  
Boundary Condition ◽  
Heat Conduction ◽  
Temperature Distribution ◽  
Thermal Stresses ◽  
Thermal Boundary Condition ◽  
Transient Temperature ◽  
Inverse Heat Conduction ◽  
Transient Temperature Distribution ◽  
Power Boiler

Determination of temperature and thermal stresses distribution in power boiler elements with use inverse heat conduction method The following paper presents the method for solving one-dimensional inverse boundary heat conduction problems. The method is used to estimate the unknown thermal boundary condition on inner surface of a thick-walled Y-branch. Solution is based on measured temperature transients at two points inside the element's wall thickness. Y-branch is installed in a fresh steam pipeline in a power plant in Poland. Determination of an unknown boundary condition allows for the calculation of transient temperature distribution in the whole element. Next, stresses caused by non-uniform transient temperature distribution and by steam pressure inside a Y-branch are calculated using the finite element method. The proposed algorithm can be used for thermal-strength state monitoring in similar elements, when it is not possible to determine a 3-D thermal boundary condition. The calculated temperature and stress transients can be used for the calculation of element durability. More accurate temperature and stress monitoring will contribute to a substantial decrease of maximal stresses that occur during transient start-up and shut-down processes.

Thermal Aspects of Grinding: The Effect of the Wheel Bond on Heat Transfer to an Abrasive Grain

1991 ◽  
Vol 113 (4) ◽  
pp. 395-401 ◽  
Author(s):  
M. W. Harris ◽  
A. S. Lavine
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Thermal Properties ◽  
Heat Conduction ◽  
Beneficial Effect ◽  
Surface Temperature ◽  
Thermal Damage ◽  
High Thermal Conductivity ◽  
Abrasive Grain ◽  
Grain Surface

Heat generated during grinding can cause thermal damage to the workpiece and wheel. It is therefore important to understand the thermal aspects of grinding. This paper addresses heat conduction into the wheel, by considering a single abrasive grain in contact with the workpiece. In particular, the effect of the bond material on conduction into the grain is investigated. The results for the grain surface temperature are given in terms of parameters describing the geometry and thermal properties of the grain and bond. The beneficial effect of a high thermal conductivity for both the grain and the bond is clearly demonstrated.

scholarly journals Slip Effects on Boundary Layer Flow and Heat Transfer Along a Stretching Cylinder

2013 ◽  
Vol 18 (2) ◽  
pp. 447-459 ◽  
Author(s):  
S. Mukhopadhyay ◽  
R.S.R Gorla
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Differential Equations ◽  
Boundary Layer Flow ◽  
Numerical Solutions ◽  
Velocity Slip ◽  
Heat Equations ◽  
Stretching Cylinder ◽  
Linear Ordinary Differential Equations ◽  
Layer Flow

An axi-symmetric laminar boundary layer flow of a viscous incompressible fluid and heat transfer towards a stretching cylinder is presented. Velocity slip is considered instead of the no-slip condition at the boundary. Similarity transformations are used to convert the partial differential equations corresponding to the momentum and heat equations into non-linear ordinary differential equations. Numerical solutions of these equations are obtained by the shooting method. It is found that the velocity decreases with increasing the slip parameter. The skin friction as well as the heat transfer rate at the surface is larger for a cylinder compared to those for a flat plate.

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