Download
1 / 15
150 likes | 738 Views
Numerical Investigation on the Heat Transfer from the Cooking Stove to the Thermoacoustic Engine’s Regenerator . David Khoo Wee Yang Yousif Abdalla Abakr Normah Mohd Ghazali. Overview . Introduction What is thermoacoustic engine ? SCORE TAE Objective Numerical Approach GAMBIT
E N D
Numerical Investigation on the Heat Transfer from the Cooking Stove to the Thermoacoustic Engine’s Regenerator David Khoo Wee Yang YousifAbdallaAbakr NormahMohdGhazali
Overview Introduction What is thermoacoustic engine ? SCORE TAE Objective Numerical Approach GAMBIT Mesh FLUENT S2S radiation model Regenerator Results Conclusion & Future works
Introduction What is thermoacoustic engine (TAE) ? SCORE TAE [2,3,4] The recent focus of SCORE engine is to use of wood instead of propane as heat source to generate electricity . Recent SCORE Demo 2 engine design, the bulge is substituted by a convolution. • Ref 2 -C. R. Saha, Paul H. Riley, J. Paul, Z. Yu, A. J. Jaworski and C. M. Johnson “Halbach array linear alternator for thermo-acoustic engine” Sensors and Actuators (2012). • Ref 3 -Paul H. Riley, Saha C, and Johnson C. J. “Designing a Low-Cost, Electricity Generating Cooking Stove” Technology and Society Magazine IEEE (2010). • Ref 4 - www.score.uk.com
Introduction SCORE TAE (Cont)
Objective To find an ideal shape of the bulge which transports heat from the flames to regenerator. To investigate the heat transfer between the regenerator and the bulge (or convolution). Two modes of heat transfers : convection & radiation. Three different bulge designs and convolution.
Y X Z Numerical Approach Gambit Porous region (regenerator) & Bulge/Convolution zone Mesh (Hexahedral & Quadrilateral) Bulge Convolution
Numerical Approach Mesh One-semicircular bulge Two-semicircular bulge Four-semicircular bulge Convolution
Numerical Approach Fluent Boundary conditions Periodic pressure inlet (UDF with 674 K) Pressure outlet Bulge / Convolution wall (T = 1024 K) Adiabatic walls (Do not participate in S2S radiation) S2S radiation model The radiosity [6,7]: • Ref 6 - ImadQashou, HoomanVahediTafreshi, BehnamPourdeyhimi “An Investigation of the Radiative Heat Transfer through Nonwoven Fibrous Materials” • Journal of Engineered Fibers and Fabrics (2009). • Ref 7 - Fluent Inc. “Fluent 6.3 User’s Guide” (2006).
Numerical Approach Regenerator A momentum source term. The source term composes of two parts; a viscous loss term and an inertia loss term [8,9]: The porous coefficients based on experimental pressure and velocity data [9]. Ref 8 - Yizhou Yan and RizwanUddin “Cfd Simulation of a Research Reactor” American Nuclear Society Topical Conference (2005). Ref 9 - Fluent Inc. “Fluent 6.3 User’s Guide” (2006).
Numerical Approach Regenerator (Cont) Viscous resistance factor (reciprocal of permeability), Inertial resistance factor,
Results Contour of temperature distribution at XY plane when Z = 0.1 m for all the geometries at t = 7.9 seconds.
Results Total heat flux, convection heat flux and radiation heat flux for one-semicircular cylinder, two-semicircular cylinder and four-semicircular cylinder at Z = 0.1 m on the bulge surface at t = 15.7 s
Results Total heat flux, convection heat flux and radiation heat flux for convolution at Z = 0.1 m on the convolution surface at t = 15.7 s
Conclusion & Future Works A new approach of studying the heat transfer in the SCORE engine. Convolution has relatively higher convection . Conduction must also be included. Operating parameters and properties can be of crucial importance. Validation with the experimental results.
