Heat Transfer, Combustion Commons^™

Computation Of 2-D And 3-D Natural Convection Heat Transfer In Closed And Vented Cavities, T. O. Mohieldin

Mechanical & Aerospace Engineering Theses & Dissertations

The natural convective heat transfer in closed and vented cavities has been studied numerically, using the primitive variables formulation. A two-and three-dimensional enclosure, and a two-dimensional Trombe Wall channel geometries are considered. The flow has been assumed to remain Laminar, and Boussinesq approximation is invoked for solving the governing equations, The finite-difference method used in this study, is based on the SIMPLER algorithm which uses a combination of central and upwind differencing scheme to obtain stable numerical results.

For both geometries, namely the closed and vented cavities, the fundamental nature of the fluid dynamic and heat transfer characteristics is revealed …

Convective Heat Transfer From Circular Cylinders Located Within Perforated Cylindrical Shrouds, Kamran Daryabeigi

Mechanical & Aerospace Engineering Theses & Dissertations

The influence of perforated cylindrical shrouds on the convective heat transfer to circular cylinders in transverse flow has been studied experimentally. Geometries studied were similar to those used in industrial platinum resistance thermometers. The influence of Reynolds number, ventilation factor (ratio of the open area to the total surface area of shroud), radius ratio (ratio of shroud's inside radius to bare cylinder's radius), and shroud orientation with respect to flow were studied.

The experiments showed that perforated shrouds with ventilation factors in the range 0.1 to 0.4 and radius ratios in the range 1.1 to 2.1 could enhance the convective …

Design Of A Combustion System Simulating Waste Heat Recovery From Diesel Engine Exhaust Gases, Nikolaos Papadopoulos

Mechanical & Aerospace Engineering Theses & Dissertations

A forced-draft laboratory combustion system simulating diesel engine exhaust gas volume flow rate and temperature conditions for waste energy recovery is analyzed and discussed. The system consists of a fan which supplies the air. The slightly compressed air is then ducted through a combustor where it is heated, and then to an air-quencher where it is cooled to a desired temperature. Finally, the air is sent through a heat exchanger, after a diffuser process, for waste heat recovery.

A gas dynamic analysis has been performed for each component part as well as a parametric study via a computer program in …

Experiments On Melting Around An Isothermal Horizontal Cylinder Under Computer Control, Timothy Moore Rothgeb

Mechanical & Aerospace Engineering Theses & Dissertations

The melting of a solid around an isothermal horizontal cylinder is a physical phenomenon which must be understood when attempting to design a latent heat storage system. The desire to design such a system is the motivating factor in this research. To gain this understanding of the fundamental melting processes several experiments were designed, and two sets of Stefan and Rayleigh number experiments were undertaken. Experiments were also performed to determine the properties of the paraffin that was used in these investigations. During the investigations of the melting processes, the temperature was measured at several locations throughout the liquid and …

A Method For Improving The Accuracy In Phase Change Heat Transfer Data Through Increased Precision In Thermophysical Property Determinations, John Philip Drummond

Mechanical & Aerospace Engineering Theses & Dissertations

Wind tunnel model materials typically have thermophysical properties that vary with both position and temperature. A numerical study using a finite difference representation of the heat conduction equation has been performed on several of these model materials to determine their thermal response under a specified heat loading. This study has confirmed the feasibility of using an effective thermophysical property to account for the existence of variable thermal properties when a model undergoes aero­ dynamic heating. The effective property, when used in the reduction of phase-change heat transfer data, forced agreement of the actual transient behavior of a model with the …

An Experimental Investigation Of The Vortex Sink Rate Sensors, Nelson L. Lu

Mechanical & Aerospace Engineering Theses & Dissertations

The vortex sink rate sensor device consists basically of an ideal sink flow between two coaxial disks. A sink tube was located at the center of one disk. The vortex was created by the rotation of the unit about its axis of symmetry. Five inch and 10 inch diameter of porous couplers were used for the air chamber here in this investigation. Several slenderness parameters, i.e., the ratio of the sink tube diameter to the height of the air chamber ^ro/n were conducted. Two probes were used to measure the static pressure and stagnation pressure respectively at various positions …

A Numerical Solution To The Problem Of Rotation Near The Ground, David D. Chen

Mechanical & Aerospace Engineering Theses & Dissertations

No abstract.