Potential of porous media combustion technology for household applications.

Households are major energy consumers and have a significant contribute to the World’s final energy consumption and CO2 emissions. Among the energy end-use in buildings lies cooking. The energy saving potential of cooking appliances is large and an investment on the development of more efficient and less polluting stoves and ovens is necessary. Porous medium combustion, already commercially available for several other applications, is a promising technology that can be applied also to household cooking. This paper reviews the research works done in the field. The number of papers dedicated to this specific application is relatively low, and most of them concentrate on experimentally proving the advantages of porous burners when compared to conventional solutions. The influence of burner characteristics and operating conditions are analysed in a few studies. However, there is still a considerable scope for the development of enhanced porous burners for household applications

Development Of Municipal Solid Waste Generation And Recyclable Components Rate Of Kuala Lumpur: Perspective Study.

This paper presents a forecasting study of municipal solid waste generation (MSWG) rate and potential of its recyclable components in Kuala Lumpur, the capital city of Malaysia. The generation rates and composition of solid wastes of various classes such as street cleansing, landscape & garden, industrial & constructional, institutional, residential and commercial are analyzed

Energy and economic analysis of Vacuum Insulation Panels (VIPs) used in non-domestic buildings

The potential savings in space heating energy from the installation of Fumed Silica (FS) and Glass Fibre (GF) Vacuum Insulation Panels (VIPs) were compared to conventional expanded polystyrene (EPS) insulation for three different non-domestic buildings situated in London (UK). A discounted payback period analysis was used to determine the time taken for the capital cost of installing the insulation to be recovered. VIP materials were ranked using cost and density indexes. The methodology of the Payback analysis carried out considered the time dependency of VIP thermal performance, fuel prices and rental income from buildings. These calculations show that VIP insulation reduced the annual space heating energy demand and carbon dioxide (CO2) emissions by approximately 10.2%, 41.3% and 26.7% for a six storey office building, a two floor retail unit building and a four storey office building respectively. FS VIPs had the shortest payback period among the insulation materials studied, ranging from 2.5 years to 17 years, depending upon the rental income of the building. For GF VIPs the calculated payback period was considerably longer and in the case of the typical 4 storey office building studied its cost could not be recovered over the life time of the building. For EPS insulation the calculated payback period was longer than its useful life time for all three buildings. FS VIPs were found to be economically viable for installation onto non-domestic buildings in high rental value locations assuming a lifespan of up to 60 years

Effect of wing deformation on the aerodynamic performance of flapping wings: fluid-structure interaction approach

Wing stiffness is very crucial in augmenting aerodynamic forces in flapping wing flyers. In this work, the effect of wing deformation was studied using three-dimensional numerical analysis (two-way fluid structure interaction), coupling the flow solver (FLUENT) and the structural (ABAQUS) solver via the MpCCI platform. Three different degrees of bending stiffness corresponding to rigid, flexible, and highly flexible case wings were investigated. Moreover, the wings were tested for both low Reynolds number (R=9,000) and high Reynolds number (R=40,000), at a flapping frequency of 9 Hz corresponding to an angle of attack (AoA) ranging from α=0 to 50°. The results of mean aerodynamic lift and drag coefficients showed good agreement between numerical and experimental findings. Also, the time-averaged lift-to-drag ratio reveals that the highly flexible wing exhibited the best overall aerodynamic performance when compared to the rigid and flexible wing

Computational unsteady flow analysis for third-grade fluid from an isothermal vertical cylinder through a Darcian porous medium

The present paper describes a mathematical model for free-convective laminar incompressible boundary layer flow of a third-grade fluid of the Reiner-Rivlin differential type, external to a uniformly heated semi-infinite vertical cylinder embedded in a two-dimensional porous medium. Assuming a homogenous-isotropic porous medium, simulation of bulk drag effects at low Reynolds number is conducted with the Darcy model. The resulting partial differential equation boundary value problem is normalized using suitable transformation variables. The highly non-linear time-dependent coupled conservation equations along with boundary conditions are solved computationally with an optimized Crank-Nicolson finite difference code. Validation with previous studies is included. The heat transport and skin friction coefficients are computed for different values of emerging non-dimensional parameters. Furthermore, steady-state and transient fluid-flow variables are shown graphically. An enhanced fluid velocity is observed for increased Darcy number and the reverse trend is computed for higher values of third-grade viscoelastic parameter. Also, the rate of heat transfer is observed to increase with greater Darcy number and a reduction in third-grade viscoelastic parameter. A key observation which is drawn from the present study is that for third-grade fluid the flow variables deviate significantly from a hot cylindrical wall as compared to a Newtonian fluid. The study is relevant to thermal polymer coating applications in aerospace materials processing

Comparative study on porous media combustion characteristics using different discrete materials

Occurrence of combustion phenomenon in porous media has always excited researchers to develop various shape and size of burner so that maximum utilization of energy can be taken achieved. Here in this experiential work, dual layer micro burner was exclusively built to carry out porous media combustion characteristic with different type of discrete material in reaction zone. Presently, only alumina and zirconia are compared in discrete form, while preheat layer was made of porcelain ceramic material (foam type). Reaction zone was restricted to thickness of 20mm while preheat zone at 10mm. A concept of equivalence ratio was aided since it involves premixed combustion of air and butane as fuel mixture. Additionally, burner was made to run under lean to ultra-lean modes and finest temperature were recorded. Both surface and submerged flame was generated effectively. Maximum temperatures recorded during surface and submerged flame condition was better by installing alumina rather than zirconia there by reaching a value of 631°C and 470°C respectively. Thus maximum thermal efficiency was calculated and found out to be 84%. Finally, emission parameters like NOx and CO where monitored and found out to be well within acceptable limits