Direct estimation of local convective boiling heat transfer coefficient in mini-channel by using conjugated gradient method with adjoint equation

The purpose of this paper was to present an inverse heat conduction method used for determining the local convective boiling heat transfer coefficient in mini-channel for pure water, copper nanofluid by using three different concentrations of nanoparticles: 5 mg/L, 10 mg/L and 50 mg/L. Conjugated gradient method with adjoint equation is used to solve the IHCP and estimate directly the space-variable convective heat transfer coefficient. Direct estimation local convective boiling heat transfer coefficient is a nonlinear inverse heat problem. The uncertainties in the estimated in heat transfer coefficient are calculated using bias and variance errors. This method is able to estimate local convective boiling heat transfer coefficient very well.