Optimal Spacing Between Pin Fins With Impinging Flow

Abstract

This is an experimental numerical and theoretical study of the heat transfer on a pin-finned plate exposed to an impinging air stream. The pin fins are aligned with the air approach velocity. The base plate and the fin cross section are square. It is demonstrated experimentally that the thermal conductance between the plate and the air stream can be maximized by selecting the fin-to-fin spacing S. Next, a simplified numerical model is used to generate a large number of optimal spacing and maximum heat transfer data for various configurations, which differ with respect to fin length (H), fin thickness (D), base plate size (L), fluid type (Pr), and air velocity (ReL). Finally, the behavior of the optimal spacing data is explained and correlated theoretically based on the intersection of asymptotes method. The recommended correlations for optimal spacing, Sopt/L ≅ 0.81 Pr−0.25 ReL−0.32, and maximum thermal conductance, (q/ΔT)max/kaH ≅ 1.57 Pr0.45 ReL0.69 (L/D)0.31, cover the range D/L = 0.06 − 0.14, H/L = 0.28−0.56, Pr = 0.72−7, ReD = 10−700, and ReL = 90−6000.

Optimization Under Uncertainty Applied to Heat Sink Design

“…Similar studies for forced convection were performed by Nakayama et al [8] and Bejan and Sciubba [9]. Ledezma et al [10] demonstrated the existence of an optimal spacing between pin fins in crossflow and impinging flow. Based on theoretical arguments relating to similarity of flow and heat transfer, the form of the correlation was borrowed from previous studies on cross-flow over staggered cylinders [7] and flow between parallel plates [9].…”

“…Problem parameters, such as base and fin dimensions and flow speeds, are matched with Ref. [10]. The OUU framework developed here is verified against simple analytical and 2D problems, such as flow in a channel with uncertain viscosity [13,14].…”

“…The OUU framework developed here is verified against simple analytical and 2D problems, such as flow in a channel with uncertain viscosity [13,14]. The deterministic computational model is first verified for the flow speeds and dimensions considered by Ledezma et al [10]. The pin-fin geometry is then optimized by considering uncertainties in the geometric and operating conditions.…”

“…The objective of the present study is to assess the importance of considering these uncertainties. Optimization under uncertainty is performed for the representative case of impinging flow on pin fins considered by Ledezma et al [10]. Problem parameters, such as base and fin dimensions and flow speeds, are matched with Ref.…”

Numerical investigation of the simultaneous influence of swirling flow and obstacles on plate in impinging jet

“…Minimum amount of heat transfer occurs at r/D=1.3 and the second peak heat transfer at r/D=1.8. Ledezma et al [4] numerically and experimentally investigated heat transfer in finned plate with impinging flow. They found an equation for optimum fin distances and the maximum thermal conductivity.…”