Heat Transfer Enhancement by Shot Peening of Stainless Steel

Abstract

In heat exchange applications, the heat transfer efficiency could be improved by surface modifications. Shot peening was one of the cost-effective methods to provide different surface roughness. The objectives of this study were (1) to investigate the influences of the surface roughness on the heat transfer performance and (2) to understand how the shot peening process parameters affect the surface roughness. The considered specimens were 316L stainless steel hollow tubes having smooth and rough surfaces. The computational fluid dynamics (CFD) simulation was used to observe the surface roughness effects. The CFD results showed that the convective heat transfer coefficients had linear relationships with the peak surface roughness (Rz). Finite element (FE) simulation was used to determine the effects of the shot peening process parameters. The FE results showed that the surface roughness was increased at higher sandblasting speeds and sand diameters.

Comparative investigation on heat transfer enhancement of surface‐roughened and nano‐dispersed phase change material for thermal energy storage

“…Therefore, considering the effect of contributing factors that includes PCM's thermal conductivity and rate of heat transfer during the melting/ solidification process, the major objective of the present work is to comparatively evaluate the charging (melting) and discharging (solidification) heat transfer characteristics of the PCM encapsulated in a novel artificially roughened (shot‐peened) spherical capsule and PCM loaded with Al 2 O 3 nanoparticle respectively. The novel attempt of shot‐peened encapsulation was considered based on its advantages such as cost‐effectiveness and improved thermal performance 43,44 . The performances of the above two augmentation techniques are compared with the performance of plain PCM encapsulated in a spherical capsule to identify the best suitable technique for effective heat transfer enhancement.…”