A Novel Topology Optimization Approach for Flow Power Loss Minimization Across Fin Arrays

Ali Ghasemi,Ali Elham

doi:10.3390/en13081987

Abstract

Fin arrays are widely utilized in many engineering applications, such as heat exchangers and micro-post reactors, for higher level of fluid–solid contacts. However, high fluid pressure loss is reportedly the major drawback of fin arrays and a challenge for pumping supply, particularly at micro-scales. Previous studies also indicate that fin shapes, spacing and alignment play an important role on the overall pressure losses. Therefore, we present a numerical tool to minimize pressure losses, considering the geometrical aspects related to fin arrays. In this regard, a density-based topology optimization approach is developed based on the pseudo-spectral scheme and Brinkman penalization in 2D periodic domains. Discrete sensitives are derived analytically and computed at relatively low cost using a factorization technique. We study different test cases to demonstrate the flexibility, robustness and accuracy of the present tool. In-line and staggered arrays are considered at various Reynolds numbers and fluid–solid volume fractions. The optimal topologies interestingly indicate a pressure loss reduction of nearly 53.6 % compared to circular fins. In passive optimization test examples, the added solid parts reduced pressure loss of a circular fin ( 9 % ) by eliminating the flow separation and filling the wake region.

Highlights

Fin array (FA) structural designs are broadly utilized in many devices which require a significant level of fluid–solid contact
Previous numerical and experimental studies on isothermal single-phase flow across fin arrays suggest that geometrical attributes, such as fin shape, alignment and pitch-space play a significant role on the total flow pressure drop [5,6,7,8]
We presented a novel topology optimization tool for hydrodynamic drag minimization of fin arrays

Summary

Introduction

Fin array (FA) structural designs are broadly utilized in many devices which require a significant level of fluid–solid contact. The promising performance of FAs, comes with the price of high pressure drop [3,4], which can be very challenging for pumping supply, at micro-scales or applications with space limitations. Previous numerical and experimental studies on isothermal single-phase flow across fin arrays suggest that geometrical attributes, such as fin shape, alignment and pitch-space play a significant role on the total flow pressure drop [5,6,7,8]. In this work, we utilize a density-based topology optimization approach to find the optimal fin geometries which minimize flow pressure drop (power loss), considering the designing aspects of fin arrays, and develop a numerical tool for this purpose. Towards minimizing pressure drops by improving fin geometry, topology optimization (TO) [9]

Objectives

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Results

Conclusion