An Inverse Analysis Method for Estimation of Heat Flux and Temperature-Dependence of Heat Transfer Coefficient

2011 ◽  
Author(s):  
Shiro Kubo ◽  
Seiji Ioka
Keyword(s):  
Heat Transfer ◽  
Surface Temperature ◽  
Inverse Method ◽  
Thermal Stresses ◽  
Temperature History ◽  
Inner Surface ◽  
History Of ◽  
Transient Thermal ◽  
The Relationship ◽  
Inverse Analysis Method

Transient thermal stresses develop in pipes during start-up and shut-down. In previous papers the present authors [1–4] proposed an inverse method for determining the optimum thermal inlet liquid temperature history which reduced the maximum transient thermal stress in pipes. The papers considered multiphysics including heat conduction, heat transfer, and elastic deformation. The inverse method used the relationship between inner surface temperature history, transient temperature distribution and transient thermal stresses. The coefficient of heat transfer plays an important role in the evaluation of thermal stress. In this study an inverse method was developed for estimating heat flux and temperature-dependence of the coefficient of heat transfer from the history of the outer surface temperature and the liquid temperature. The method used the relationship between the outer surface temperature and the inner surface temperature. For the regularization of solution the function expansion method was applied in expressing the history of flux on the inner surface. Numerical simulations demonstrated the usefulness of the proposed inverse analysis method. By examining the effect of measurement errors of temperature on the estimation, the robustness of the method was shown.

An Inverse Method for Determining Thermal Load History Which Reduces Transient Thermal Stress

2006 ◽  
Author(s):  
Takuya Ishizaka ◽  
Shiro Kubo ◽  
Seiji Ioka
Keyword(s):  
Heat Transfer ◽  
Thermal Stress ◽  
Temperature Distribution ◽  
Thermal Load ◽  
Inverse Method ◽  
Temperature History ◽  
Load History ◽  
Transient Thermal Stress ◽  
Inner Surface ◽  
Transient Thermal

When high temperature fluid flows into a pipe, a temperature distribution in the pipe induces a thermal stress. It is important to reduce the thermal stress for managing and extending the lives of plants. In this problem heat conduction, elastic deformation, heat transfer, liquid flow should be considered, and therefore the problem is of multidisciplinary nature. In this paper an inverse method is proposed for determining the optimum thermal load history which reduces transient thermal stress considering the multidisciplinary physics. As a typical problem, transient thermal stress in a thin pipe during start-up was treated. It was assumed that the inner surface was heated by liquid flow and the outer surface was insulated for simplicity. The multidisciplinary complex problem was decomposed into a heat conduction problem with given internal wall temperature history, thermal stress problem with given temperature distribution, and heat transfer problem with given heat flux on an inner surface. An analytical solution of the temperature distribution of the radial thickness and the thermal hoop stress distribution was obtained. The maximum inner hoop tensile stress was minimized for the case where inner surface temperature Ts(t) was expressed in terms of the 3rd order polynomial function of time t. Finally, from the temperature distributions, the optimum fluid temperature history was obtained for reducing the transient thermal tensile stress.

Identification of three-dimensional transient temperature fields in thick-walled elements using the inverse method

2018 ◽  
Vol 28 (1) ◽  
pp. 138-150 ◽  
Author(s):  
Magdalena Jaremkiewicz
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Inverse Method ◽  
Thermal Stresses ◽  
Computing Time ◽  
Transient Temperature ◽  
Content Type ◽  
Inner Surface ◽  
The Heat Transfer Coefficient

Purpose The purpose of this paper is to propose a method of determining the transient temperature of the inner surface of thick-walled elements. The method can be used to determine thermal stresses in pressure elements. Design/methodology/approach An inverse marching method is proposed to determine the transient temperature of the thick-walled element inner surface with high accuracy. Findings Initially, the inverse method was validated computationally. The comparison between the temperatures obtained from the solution for the direct heat conduction problem and the results obtained by means of the proposed inverse method is very satisfactory. Subsequently, the presented method was validated using experimental data. The results obtained from the inverse calculations also gave good results. Originality/value The advantage of the method is the possibility of determining the heat transfer coefficient at a point on the exposed surface based on the local temperature distribution measured on the insulated outer surface. The heat transfer coefficient determined experimentally can be used to calculate thermal stresses in elements with a complex shape. The proposed method can be used in online computer systems to monitor temperature and thermal stresses in thick-walled pressure components because the computing time is very short.

Development of Inverse Analysis of Heat Conduction and Thermal Stress for Elbow: Part I

2013 ◽  
Author(s):  
Seiji Ioka ◽  
Shiro Kubo ◽  
Mayumi Ochi ◽  
Kiminobu Hojo
Keyword(s):  
Heat Conduction ◽  
Thermal Stress ◽  
Transfer Function ◽  
Surface Temperature ◽  
Outer Surface ◽  
Inverse Analysis ◽  
Temperature History ◽  
Analysis Method ◽  
Inner Surface ◽  
Inverse Analysis Method

Thermal fatigue may develop in piping elbow with high temperature stratified flow. To prevent the fatigue damage by stratified flow, it is important to know the distribution of thermal stress and temperature history in a pipe. In this study, heat conduction inverse analysis method for piping elbow was developed to estimate the temperature history and thermal stress distribution on the inner surface from the outer surface temperature history. In the inverse analysis method, the inner surface temperature was estimated by using the transfer function database which interrelates the inner surface temperature with the outer surface temperature. Transfer function database was calculated by FE analysis in advance. For some patterns of the temperature history, inverse analysis simulations were made. It was found that the inner surface temperature history was estimated with high accuracy.

Quantification of thermal energy generation in annular hyperbolic porous-finned heat sinks using inverse optimization

2021 ◽  
pp. 095440892110243
Author(s):  
Sagnik Pal ◽  
Ranjan Das
Keyword(s):  
Heat Transfer ◽  
Surface Temperature ◽  
Heat Generation ◽  
Thermal Energy ◽  
Inverse Method ◽  
Golden Section ◽  
Energy Generation ◽  
Heat Sinks ◽  
Search Technique ◽  
Golden Section Search

The present paper introduces an accurate numerical procedure to assess the internal thermal energy generation in an annular porous-finned heat sink from the sole assessment of surface temperature profile using the golden section search technique. All possible heat transfer modes and temperature dependence of all thermal parameters are accounted for in the present nonlinear model. At first, the direct problem is numerically solved using the Runge–Kutta method, whereas for predicting the prevailing heat generation within a given generalized fin domain an inverse method is used with the aid of the golden section search technique. After simplifications, the proposed scheme is credibly verified with other methodologies reported in the existing literature. Numerical predictions are performed under different levels of Gaussian noise from which accurate reconstructions are observed for measurement error up to 20%. The sensitivity study deciphers that the surface temperature field in itself is a strong function of the surface porosity, and the same is controlled through a joint trade-off among heat generation and other thermo-geometrical parameters. The present results acquired from the golden section search technique-assisted inverse method are proposed to be suitable for designing effective and robust porous fin heat sinks in order to deliver safe and enhanced heat transfer along with significant weight reduction with respect to the conventionally used systems. The present inverse estimation technique is proposed to be robust as it can be easily tailored to analyse all possible geometries manufactured from any material in a more accurate manner by taking into account all feasible heat transfer modes.

Simplified Procedure for Prediction of Asphalt Pavement Subsurface Temperatures Based on Heat Transfer Theories

1997 ◽  
Vol 1568 (1) ◽  
pp. 114-123 ◽  
Author(s):  
Lisheng Shao ◽  
Sun Woo Park ◽  
Y. Richard Kim
Keyword(s):  
Heat Transfer ◽  
Surface Temperature ◽  
Air Temperature ◽  
Asphalt Pavement ◽  
Prediction Method ◽  
Point Of View ◽  
Temperature History ◽  
Climatic Regions ◽  
Simplified Procedure ◽  
Subsurface Temperatures

Surface deflection measurements and backcalculation of layer moduli in flexible pavements are significantly affected by the temperature of the asphalt concrete (AC) layer. Correction of deflections or backcalculated moduli to a reference temperature requires determination of an effective temperature of the AC layer. For routine deflection testing and analysis in state highway agencies, it is preferable, from a practical point of view, to use a nondestructive prediction method for determining the effective AC layer temperature instead of measuring the temperature directly from a small hole drilled into the AC layer. A simplified procedure to predict asphalt pavement subsurface temperatures is presented. The procedure is based on fundamental principles of heat transfer and uses the surface temperature history since yesterday morning to predict the AC layer mid-depth temperature at the time of falling weight deflectometer (FWD) testing today. The surface temperature history is determined using yesterday’s maximum air temperature and cloud condition, the minimum air temperature of today’s morning, and surface temperatures measured during FWD tests. FWD tests and temperature measurements have been conducted on seven pavement sections with varying structural designs located in three different climatic regions of North Carolina. The field temperature records from these pavements have provided values of pavement thermal parameters and coefficients in temperature functions that are needed in the prediction procedure. A set of verification results are presented using examples with different climatic regions, changing AC layer thicknesses, and varying weather patterns in different seasons.

A Review of Temperature Reduction Methods in Codes and Standards for Pipe Supports

2020 ◽  
Author(s):  
Alex Mayes ◽  
Phillip Wiseman ◽  
Kshitij P. Gawande
Keyword(s):  
Heat Transfer ◽  
Computational Models ◽  
Thermal Stresses ◽  
Geometrical Parameters ◽  
Atmospheric Conditions ◽  
Closed Form Solutions ◽  
Temperature Reduction ◽  
Reduction Methods ◽  
American Society ◽  
Transient Thermal

Abstract American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code, Section III, Division 1, Subsection NF, Subparagraph NF-3121.11 does not require that thermal stresses in supports be evaluated. Historically, pipe support engineers have not been concerned with thermal stresses of pipe and component supports, but determining material temperature limits and allowable stresses have been a major role in designing and analyzing supports. Thus, heat transfer is often investigated in finding the temperature of pipe supports and parts of pipe supports that are not in direct contact with pipe or pipe components. There are also other Codes and standards that permit a reduction of temperature away from the outer surface of pipe or pipe components. In some but not all cases, Codes and standards explicitly address reduction of temperature for applications of utilizing thermal insulation. Additionally, the temperature distribution is established by specific geometrical parameters and their respective equations for employment by the pipe support engineer. These reductions are explored by utilizing fundamentals of heat transfer. Additionally, steady-state and transient thermal Finite Element Analyses (FEA) are used to establish computational models of simple geometric bodies in a range of atmospheric conditions. The effects of insulation on the thermal distribution are also represented through closed form solutions and FEA. The results of these analyses allow for assessment of, and recommendations for, the treatment of temperature reduction in Codes and standards.

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