Estimation of Heat Transfer Coefficient and Reference Temperature in Jet Impingement Using Solution to Inverse Heat Conduction Problem Anil R. Kadam, Vijaykumar Hindasageri and G. N. Kumar Abstract The heat transfer estimation in case of impinging jets has been considered by mainly steady-state techniques. The present study reveals the transient technique to characterize the impinging jets. A solution to three-dimensional inverse heat con- duction problem (IHCP) is used to estimate the unknown transient surface tempera- ture distribution at the jet impinging side (front side) from known non-impingement side (backside) transient temperature distribution. Further to estimate front side heat flux distribution, the temperature gradient close to the front surface is computed by finite difference method, and then linearity between surface heat flux and corre- sponding surface temperature is utilized to find out heat transfer coefficient (HTC) and the reference temperature simultaneously. To validate and establish the present technique, numerical simulations are carried out in fluent. The numerically estimated back surface temperature data is used as input to the solution to IHCP. Hot as well as cold impinging jets are characterized with the help of this solution. Along with lam- inar jets, turbulent jets with varying Reynolds number are considered. The inversely estimated results are compared with numerically simulated data and match is within 1%. Keywords IHCP · Heat transfer coefficient · Reference temperature Impinging jet A. R. Kadam · G. N. Kumar Department of Mechanical Engineering, National Institute of Technology, Surathkal 575025, Karnataka, India V. Hindasageri (B ) Department of Mechanical Engineering, KLS Vishwanathrao Deshpande Rural Institute of Technology, Haliyal 581329, Karnataka, India e-mail: vkhnitk@gmail.com © Springer Nature Singapore Pte Ltd. 2019 D. Srinivasacharya and K. S. Reddy (eds.), Numerical Heat Transfer and Fluid Flow, Lecture Notes in Mechanical Engineering, https://doi.org/10.1007/978-981-13-1903-7_5 31