Methodological and experimental aspects of the estimation of transient heat transfer coefficients in quenching experiments, using inverse heat transfer methods, were addressed and investigated. Beck’s method was used for the estimation of the transient heat transfer coefficient history from interior transient temperature measurements during quenching. Experiments involved plunging a high-purity copper sphere into cooling baths without boiling. The sphere was instrumented with several interior thermocouples for measuring the transient temperature response during quenching. Water and ethylene glycol were investigated. The early transient values of the heat transfer coefficient history were found to be about 100–120 percent higher than the values predicted using well-known empirical correlations for free convection. The later time values were in good agreement with those predicted with empirical correlations. The transient inverse technique has the capability of estimating early transients and subsequent quasi-steady-state values of heat transfer coefficient in a single transient experiment.

This paper presents a method for calculating the heat flux at the surface of a body from experimentally measured transient temperature data, which has been called the inverse heat conduction problem (IHCP). The analysis allows for two-dimensional heat flow in an arbitrarily shaped body and orthotropic temperature dependent thermal properties. A combined function specification and regularization method is used to solve the IHCP with a sequential-in-time concept used to improve the computational efficiency. To enhance the accuracy, the future information used in the sequential-in-time method and the regularization parameter are variable during the analysis. An example using numerically simulated data is presented to demonstrate the application of the method. Finally, a case using actual experimental data is presented. For this case, the boundary condition was experimentally measured and hence, it was known. A good comparison is demonstrated between the known and estimated boundary conditions for the analysis of the numerical, as well as the experimental data.

No abstract

No abstract

No abstract