Experimental and numerical study of the additive layer manufactured inter-layer channel heat exchanger

• Published in: Applied thermal engineering 2021-04, Vol.188, p.116501, Article 116501
• Main Authors: Greiciunas, Evaldas, Borman, Duncan, Summers, Jonathan, Smith, Steve J.
• Format: Article
• Language: English
• Subjects: Additive Layer Manufacturing (ALM); Aluminum; Computation Fluid Dynamics (CFD); Conjugate Heat Transfer (CHT); Core flow; Forced convection; He Jiankui; Heat conductivity; Heat exchangers; Heat transfer; Mass flow; Mathematical models; Numerical analysis; OpenFOAM; Simulation; Studies
• ISSN: 1359-4311; 1873-5606
• DOI: 10.1016/j.applthermaleng.2020.116501

In this paper the performance of a recently patented additive layer manufactured (ALM) concept inter-layer heat exchanger (HE) is evaluated experimentally and numerically. Two numerical HE models are developed using the conjugate heat transfer (CHT) methodology. The first is an idealised HE core model, consisting of a single period width HE corrugation section (termed superchannel). The second approach uses a fully detailed HE unit model which resolves the flow and heat transfer inside the complete HE unit. A close agreement was found between the HE unit simulations and the experimentally obtained results, such that the fully detailed HE model could be validated. It was also shown that, a full CHT approach is necessary to accurately evaluate complex inter-layer ALM HE core flow and heat transfer behaviour and can serve as an approach for optimising HE designs. The results also reinforce the occurrence of the inter-layer flow mixing inside the HE core of the same flow streams and allows the mass flow to redistribute inside the HE core which is impossible with the current HE generation geometries. The superchannel model results in a slight over-estimation in heat transfer (ΔT≈4 K on average) making the simplified model acceptable as a conservative estimate. Using validated simulations a parametric study was conducted by changing the solid properties of the full CHT HE model to aluminium to investigate the effects of a significantly more conductive material. This resulted in ≈3% higher heat transfer effectiveness (ϵ) of the HE unit. All the simulations were carried out using CFD package OpenFOAM. •A concept inter-layer heat exchanger was experimentally evaluated.•A good agreement was achieved between the CHT CFD and the experiments.•Idealised superchannel HE model shows a theoretically optimal HE unit performance.•Using a more conductive material results in a small improvement in heat transfer.