Heat Transfer Between Impinging Circular Air Jet and Finned Flat Plate and Validation of Results Using Artificial Neural Network

Impinging jets on rough surfaces are important in many industrial applications. The surface may become rough for many reasons. Roughness may arise from manufacturing processes, a long time in service and/or natural occurrences such as rain, snow, frost etc. Prior research indicate that the average roughness height on in-service gas turbine blades may vary from 1.5um to 10um.This is very rough considering the thickness of the boundary layer is of the order of 1 mm.Similarly,there are some industrial applications like spray formed billet cooling by impinging jets where the target and the jet are not orthogonal but the oblique.Therefore, study of inclination of target plate on heat transfer between impinging jet and rough flat plate is important. In the present work, inclination effect is studied for the oblique angles of 45°, 60° and 75° at a given Z/D of 1 and Reynolds number of 23000. The rough surfaces are in the form of hexagonal prism of side 2.04 mm and height of 2 mm spaced at a pitch of 7.5 mm on the target plate.The experimental results are validated using Artificial Neural Network (ANN). It has been observed that the validation using ANN gives the correlation coefficient (R²) as 0.998 to 1.