8 th ICCHMT, Istanbul, 25-28 May 2015 181 COMPUTATIONAL SIMULATION OF THE HEAT AND FLUID FLOW THROUGH A ROTARY THERMAL REGENERATOR BASED ON A POROUS MEDIA APPROACH Ahmed Alhusseny 1, 2, * and Ali Turan 1 , Adel Nasser 1 1 School of MACE, The University of Manchester, Manchester, M1 1QD, UK 2 Mechanical Engineering Department, College of Engineering, University of Kufa, Najaf, Iraq *Corresponding Author: Email: ahmed.alhusseny@postgrad.manchester.ac.uk Keywords: Porous Media Approach, Rotary Regenerator, Thermal Effectiveness, Pressure Drop ABSTRACT A numerical analysis for the fluid flow and heat transport phenomenon through a rotary thermal regenerator is presented by means of employing the porous media concept. An aluminum core formed of multi packed square passages is simulated as a porous medium of an orthotropic porosity in order to allow the counter-flowing streams to flow in a way similar to that inside the regenerator core. The geometric properties of the core were transformed into the conventional porous media parameters such as the permeability and the inertial coefficient based on empirical equations; so, the core has been dealt with as a porous medium of known features. Local thermal non-equilibrium situation is assumed between both fluid and solid phases, so heat is allowed to be exchanged between them. The results are presented by means of overall temperature effectiveness, pressure drop, and the relative output power. The use of porous media approach has been found to be sufficient to solve the current problem. The data obtained reveals an obvious impact of the core geometrical parameters on both the heat restored and the pressure loss; and hence, the overall efficiency of the regenerator system. NOMENCLATURE asf solid-fluid interfacial specific surface area F inertial coefficient of the core matrix hsf solid-fluid interfacial heat transfer coefficient K permeability of the core matrix v dimensional velocity vector Greek symbols ε thermal effectiveness φ porosity of the core matrix Subscripts fe fluid effective se solid effective INTRODUCTION Mainly, there are two options available for achieving a high thermal efficiency in gas turbine systems. The first is via applying a high compression ratio, which should be accompanied with intercooling process. The second choice is applying a low compression ratio combined with recirculating heat between the cold stream and exhaust gas to recover a part of its thermal energy instead of releasing it to the environment. Heat recirculation is usually accomplished by means of two alternatives. A recuperator, in which a heat exchange between the cold and hot streams takes place across a separating wall between them. The other proposal is the regenerator, which allows heat exchange between the two streams through a common solid surface exposed to the hot and cold streams alternatively, Organ [1]. Switching between the two streams can be achieved by means of several ways. One of them, which is sometimes known as the “thermal wheel” or “rotary regenerator”, is compound of a permeable core that rotates between two fixed channels carrying hot and cold gases as shown in Fig.(1), Organ [1]. The two streams flow continuously in a counter manner through a porous core, which has an orthotropic porosity to allow both gases to flow simultaneously in separate portions. This configuration was examined experimentally by Iwai et al. [2] and later by Sayama and Morishta [3] in the context of applying gas turbines into vehicular propulsion systems. In regard to air-conditioning applications, rotary regenerators have distinct advantages over ordinary recuperators in recovering heat from exhaust air [4]. They have a substantially larger and comparatively less costly heat transfer area. In general, their efficiency is relatively higher, and hence, they have