Determination Of Heat Transfer Characteristics Employing Modified Maximum Slope Method For Porous Media Heat Exchanger Using Al2O3–Water Nanofluids

Dijin J S,Rajkumar M R,Anjan R Nair,A Mohamad,A.C Benim,R De Lieto Vollaro,S.-H Suh,G Battista,A Vallati,J Taler,R Bennacer

doi:10.1051/e3sconf/201912804011

Abstract

It has been well documented in many literature that porous media and nanofluid can augment heat transfer in many engineering system. However the combined usage of these two media has not been given much attention in literature. The objective of the present work is to experimentally investigate porous media heat exchanger using Al2O3/water nanofluids. The heat transfer characteristics is determined using transient testing method wherein, only one fluid stream flows steadily throughthe test core, then a transient perturbation in the inlet fluid temperature is induced and the outletfluid temperature variation is measured continuously. The measured data is evaluated using the maximum slope method to obtain the heat transfer characteristics. The results show an increase in Nusselt number values with the use of nanofluids in porous media heat exchanger compared to water

Highlights

In recent years, the high cost of energy and material has led to the designing of more efficient and economical heat exchangers [8,9]
The results shown improvement in convective heat transfer coefficient in the thermally fully developed regime
It is observed that the Number of Transfer Units (NTU) values decrease with increasing Reynolds Number for both water and nanofluid

Summary

Introduction

The high cost of energy and material has led to the designing of more efficient and economical heat exchangers [8,9]. The data obtained gives the fluid temperature history at the exit of the compact heat exchanger and the time at which it occurs for the prediction of NTU using the maximum slope method proposed by Krishnakumar and Venkatarathnam [2]. They established a relationship for NTU and axial conduction parameter for various combinations of maximum slope and the time at which the maximum slope occurs. Using the data NTU values were estimated for stainless steel and galvanized iron wire meshes for two different porosities

Objectives

Methods

Results

Conclusion