Experimental Estimation of Temporal and Spatial Resolution of Coefficient of Heat Transfer in a Channel Using Inverse Heat Transfer Method

TL;DR

This paper presents a novel, non-intrusive inverse method to experimentally estimate the temporal and spatial resolution of heat transfer coefficients in a channel with water flow, including phase change effects.

Contribution

It introduces an extended inverse technique using conjugate gradient method to accurately determine local heat transfer coefficients during boiling flow.

Findings

Estimated Nusselt numbers closely match existing correlations.

The inverse method effectively captures transient heat transfer changes.

The approach is applicable to boiling flows with phase change.

Abstract

In this research, a novel method to investigation the transient heat transfer coefficient in a channel is suggested experimentally, in which the water flow, itself, is considered both just liquid phase and liquid-vapor phase. The experiments were designed to predict the temporal and spatial resolution of Nusselt number. The inverse technique method is non-intrusive, in which time history of temperature is measured, using some thermocouples within the wall to provide input data for the inverse algorithm. The conjugate gradient method is used mostly as an inverse method. The temporal and spatial changes of heat flux, Nusselt number, vapor quality, convection number, and boiling number have all been estimated, showing that the estimated local Nusselt numbers of flow for without and with phase change are close to those predicted from the correlations of Churchill and Ozoe (1973) and Kandlikar (1990), respectively. This study suggests that the extended inverse technique can be successfully utilized to calculate the local time-dependent heat transfer coefficient of boiling flow.