Computational Investigation of Flow and Heat Transfer Characteristics of Impingement Cooling Channel

Abstract

Impingement cooling offers very high heat transfer coefficients. Flow field, involved in impingement cooling is dominated by stagnation zone, transition zone and developing zone. Understanding of complex flow phenomenon and its effects on heat transfer characteristics is useful for efficient designing of impingement channels. Computational fluid dynamics (CFD) has emerged as a powerful tool for the analysis of flow and heat transfer systems. Honeywell has been investigating the use of CFD to determine the characteristics of various complex turbine blade cooling heat transfer augmentation methods such as impingement. The objective of this study is to develop CFD methodology which is suitable for computational investigation of flow and heat transfer analysis of impingement cooling through validation. Single row of circular jets impinging on concave (curved) surface has been considered for this study. The validation was accomplished with the test results of Bunker and Metzger [10] and with the correlations of Chupp et al. [7]. The parameters which are varied in this study include jet Reynolds number (Re2B = 6750–10200), target plate distance to jet diameter ratio (Z/d = 3 and 4), and target surface sharpness (i.e. radius ratio, r* = 0.2, 0.4 and 1) the simulations are performed under steady state conditions. Predicted results are compared for local endwall heat transfer results along the curve length of the mid span target wall. Flow field results obtained at different locations are presented to understand the heat transfer behavior.

Conjugated investigation on the effect of rotation on the leading-edge impingement structures with and without film-cooling holes

“…The research conducted by Zuckerman and Lior 25 and Ramakumar et al 26 showed that the two-equation turbulence model can predict the flow characteristics and heat transfer of impingement cooling precisely. Therefore, this paper adopts several two-equation turbulence models: k − ε model, k − ω model, SST k − ω model, and SST k − ω model with γ − θ transition model to calculate the experimental impingement cooling cases conducted by Deng et al 16 The case with a rotating number of 0.139 and the angle between the rotation axis and the jet of 30 was selected.…”

Cooling Characteristic of a Wall Jet for Suppressing Crossflow Effect under Conjugate Heat Transfer Condition

“…[7][8][9]. The heat transfer enhancement of impingement cooling is influenced by many factors such as jet Reynolds number, jetting hole diameter, jetting hole pitch [10], jet to plate distance [11] and target wall curvature [12]. With the development of additive manufacturing, more and more researchers are focusing on combining the target surface of impingement cooling with heat transfer enhancing features, including pin-fin [13,14], micro pin-fin [15], dimple [16,17], conical and ring protuberances [18].…”