Solution Of Inverse Heat Conduction Research Articles

Erratum to “Inverse Heat Conduction Solution Utilizing Differential Method with Exact Matching Rule –– A Robustly-Stable and Easy-to-Use Scheme” [TSE Vol. 29, No. 2, pp. 33-43

Erratum to “Inverse Heat Conduction Solution Utilizing Differential Method with Exact Matching Rule –– A Robustly-Stable and Easy-to-Use Scheme” [TSE Vol. 29, No. 2, pp. 33-43

Inverse Heat Conduction Solution Utilizing the Difference Method with an Exact Matching Rule A Robustly Stable and Easy-to-Use Scheme

Inverse Heat Conduction Solution Utilizing the Difference Method with an Exact Matching Rule A Robustly Stable and Easy-to-Use Scheme

Application of an Inverse Heat Conduction Solution with Laplace Transform Technique for a Steel Cooling Processes

Application of an Inverse Heat Conduction Solution with Laplace Transform Technique for a Steel Cooling Processes

Experimental characterization of the hypersonic flow around a cuboid

Understanding the hypersonic flow around faceted shapes is important in the context of the fragmentation and demise of satellites undergoing uncontrolled atmospheric entry. To better understand the physics of such flows, as well as the satellite demise process, we perform an experimental study of the Mach 5 flow around a cuboid geometry in the University of Manchester High SuperSonic Tunnel. Heat fluxes are measured using infrared thermography and a 3D inverse heat conduction solution, and flow features are imaged using schlieren photography. Measurements are taken at a range of Reynolds numbers from {40.0 times 10^3} to {549 times 10^3}. The schlieren results suggest the presence of a separation bubble at the windward edge of the cube at high Reynolds numbers. High heat fluxes are observed near corners and edges, which are caused by boundary-layer thinning. Additionally, on the side (off-stagnation) faces of the cube, we observe wedge-shaped regions of high heat flux emanating from the windward corners of the cube. We attribute these to vortical structures being generated by the strong expansion around the cube’s corners. We also observe that the stagnation point of the cube is off-centre of the windward face, which we propose is due to sting flex under aerodynamic loading. Finally, we propose a simple method of calculating the stagnation point heat flux to a cube, as well as relations which can be used to predict hypersonic heat fluxes to cuboid geometries such as satellites during atmospheric re-entry.Graphic abstract

Monitoring of thermal stresses in pressure components based on the wall temperature measurement

Thick-wall boiler components limit maximum heating and cooling rates during start-up or shut-down of the boiler. First, the allowable heating rates of the critical pressure components of the boiler were determined, and the temperature of the fluid was determined. The rate of change of the wall temperature of the pressure element and the thermal stress on the inner surface are controlled online and compared with the permissible values. Boiler manufacturers designate thermal stresses on the inner surface of the pressure component on the edge of the hole based on the measurement of the wall temperature at two points located inside it. Due to the low accuracy of the method used by boiler manufacturers, a new stress-determination method has been proposed in this paper in which only the internal temperature measurement point is used to determine the stresses on the inner surface of the component. In the method proposed in the paper, first, the internal surface temperature is determined from the inverse heat conduction solution, and then the stresses are calculated. Numerous computational tests were performed for cylindrical and spherical elements. Thermal stresses on the inner surface were also determined based on actual measurement data. Thermal stresses can be monitored at small time intervals. The advantage of the method is its high accuracy even at rapid changes in the fluid temperature.

Boundary element analysis of inverse heat conduction problems in 2D thin-walled structures

This paper develops the boundary element method (BEM) based on potential theory for inverse analysis of heat conduction in two-dimensional (2D) thin-walled structures. The troublesome nearly-singular integrals, which are crucial in the application of the BEM to thin shapes, are efficiently handled by using a non-linear transformation technique. In conjunction with several regularization techniques, the present BEM formulation is then extended to the solution of inverse heat conduction in thin body. Due to its boundary-only discretization and semi-analytical nature, the BEM is considered a competitive technique for the solution of such inverse problems. Our numerical experiments show that the proposed BEM appears very promising even when the thickness-to-length ratio of thin shapes is as small as 1E−9, which is sufficient for modeling most thin shapes as used in smart materials and micro-electro-mechanical systems.

Solution of inverse heat conduction problem using the lattice Boltzmann method

In this paper the D2Q9 lattice Boltzmann method (LBM) was utilized for the solution of a two-dimensional inverse heat conduction (IHCP) problem. The accuracy of the LBM results was validated against those obtained from prevalent numerical methods using a common benchmark problem. The conjugate gradient method was used in order to estimate the heat flux test case. A complete error analysis was performed. As the LBM is attuned to parallel computations, its use is recommended in conjugation with IHCP solution methods.

Estimation of Uncertainty in an Analytical Inverse Heat Conduction Solution

The method of sequential perturbations is applied to find the uncertainty in estimated surface temperature and heat flux from a two-dimensional analytical inverse heat conduction problem related to impinging jet quenching experiments. It is shown that for meaningful uncertainty estimates, the inverse solution itself must be formulated such that it can be interpreted as giving average surface conditions over a small period of time and space. A procedure for estimating the time and space resolution limits of the solution is proposed.

Improvement of inverse heat conduction solution using Laplace transformation: Method of partial division of time

AbstractAny solution for an inverse heat conduction problem makes the estimation of surface temperature and surface heat flux worsen in the case where these values behave like a triangular shape change with time. In order to compensate for this defect, Monde and colleagues, who succeeded in obtaining analytical inverse solutions using the Laplace transform technique, introduce a new idea where these changes over the entire measurement time can be split into several parts depending on the behavior. Therefore, an approximate equation to trace the measured temperature change can be derived, resulting in good estimation of surface temperature and surface heat flux even in the case of the triangular shape change and sharp change. © 2003 Wiley Periodicals, Inc. Heat Trans Asian Res, 32(7): 630–638, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.10117

Improvement of Inverse Heat Conduction Solution using Laplace Transformation. (Method of Partial Division of Time).

An analytical method has been developed for inverse problem of one- and two-dimensional heat conduction by using Laplace transform technique. For the cases of radical change in a measured temperature and of a triangular shape of temperature change, a proposed function cannot approximate the temperature over the whole range of measured time so that the inverse solution obtained thereby makes its estimation deteriorate. The characteristic of Laplace transform gives this deterioration clear by splitting the whole time into a partial time. The result shows that the estimation of surface temperature and heat flux can be markedly improved on comparison of any existing one.

Experimental investigation of transient heat transfer in the once-through boiler water separator

The transient heat transfer between working fluid and inner wall of 600 MW supercritical pressure boiler’s water separator model during start-up was experimentally explored. The test conditions for water steam two-phase were as follows: pressure P=3–11 MPa, mass flow M=0.2–0.35 kg/s, and mass quality x=0.2–0.8; for subcooled water P=3–11 MPa, M=0.2–0.35 kg/s, and subcooled degree Δθ=10°C. By using an accurate and tractable inverse heat conduction solution, the correlations of single-phase and two-phase transient heat transfer coefficients were obtained. The experimental results demonstrated the heat transfer enhanced for subcooled water and water steam mixture compared with fully developed turbulent flow in tube. The increasing heat transfer effect may be attributed to the deformation or destruction of the boundary layer.

Hysteresis and contact angle effects in transition pool boiling of water

Transition boiling on a horizontal surface has been studied. Both transient heating and transient cooling were used. The heat flux into the boiling liquid is calculated from temperatures at two levels using an inverse heat conduction solution. The heat transfer is strongly affected by the value of the liquid contact angle, lower contact angles giving higher heat fluxes. Also there is pronounced hysteresis between heating and cooling with higher heat fluxes in heating. This hysteresis is observed at all contact angles.