Karim J. Nasr

An experimental and numerical study of heat transfer off an inclined surface subject to an impinging airflow

Abstract Understanding the heat transfer interaction between an impinging jet and an inclined surface is of paramount practical significance. In this paper, the heat transfer process is investigated utilizing a three-dimensional finite volume numerical method and renormalization group (RNG) theory based k–e turbulence model. The issuing incompressible jet is impinging upon the inside of an inclined surface creating a thermal boundary layer and a fully three-dimensional vortex structure. Numerical analyses predict a detailed description of fluid flow patterns and heat transfer coefficients. Experimental investigations are performed on the inner surface for the purpose of obtaining local and average heat transfer coefficients and further validation of the numerical results. The effect of different turbulence levels in the numerical solution is also reported.

DEFROSTING OF AUTOMOTIVE WINDSHIELDS: PROGRESS AND CHALLENGES

Climate control applications are of great interest to the automotive industry. The issue of windshield defrosting has received, and continues to receive, considerable attention from various investigators around the world. This paper presents an up-to-date assessment of our knowledge base on defrosting. It documents a comprehensive literature review covering experimental as well as computational efforts, accompanied by utilisation of electric heating elements, conducting films, and heat storage devices. The paper also presents a list of measurement methods for airflow and thermal patterns pertinent to defrosting. It concludes with an example on quick detection of a defroster system performance, recommends a defroster system development sequence, and addresses relevant future challenges.

Development of Problem-Based Learning Modules for Engineering Thermodynamics

Problem-Based Learning (PBL) is an instructional approach that fosters active learning, supports knowledge construction, integrates disciplines, and naturally combines classroom learning with real-life applications. This approach can be described as student-centered and concept-embedded. This paper presents the development of curricular materials in Engineering Thermodynamics that are founded on PBL, supported by technology through simulations, and target higher levels of Bloom’s Taxonomy of Learning. Thermodynamics is restructured as modules presenting practical applications first whereas principles are introduced just-in-time and as encountered. Theoretical information is presented to support the understanding of knowledge as students apply inquiry-based learning. These modules are carefully designed to reflect traditional concepts but made more exciting as students discover the need for the laws and principles. The classroom format is interactive, cooperative and revolves around students’ needs. Formative and summative assessment tools are designed to examine the effectiveness of created modules.Copyright

An experience on Industry-University collaborative research

Industry-university collaboration is common at GMI Engineering & Management Institute, USA, a fully co-operative institution which requires students to write a fifth-year thesis on a project relevant to an industrial sponsor. While the undergraduate link between GMI and its industrial sponsors is strong, collaborating on higher level research projects is somewhat new. This paper documents the phases of a collaborative research experience between GMI Engineering and Management Institute and Ford Motor Company. It also presents the potential benefits to each party, describes appropriate relationships, and exhibits steps for continuing cooperation. The paper concludes with an outline for a successful collaboration and suggests ways to ensure a fruitful experience for both industry and university participants.

Design and Development of a Convection Heating System in a Glass Tempering Furnace

Glass tempering has relied on radiant heaters to transfer heat to glass sheets. This has a direct correlation to the length of time that the glass is subject to heating in the furnace and its related line speeds. This paper presents the design and development of a supplementary convection heating system with the objective of reducing glass residence time and increasing production efficiency. It will document the methodology of retrofitting a current furnace in a cost effective manner while increasing heat transfer to the glass and increasing throughput. This study will address factors affecting the systems’ performance such as current draw, surface compression test, break pattern, warp configuration, and nozzle design. The retrofitted system has achieved design goals and promises to increase heat transfer rates to the glass as well as increase furnace productivity.Copyright

Effect of Angle and Separation Distance on Heat Transfer on an Inclined Surface Subject to Airflow

Impinging jets may be used to achieve enhanced local heat transfer for convective heating, cooling, or drying. The issuing jet may contact the surface normally or obliquely. Factors such as jet attachment, surface angle, jet angle, separation distance between jet orifice and surface of impingement, and trajectory influence heat transfer dramatically. This study addresses the thermal problem of jet impingement on an inclined surface. This investigation is motivated by the practical application of air jets issuing out of a defroster’s nozzles and impinging on the inclined windshield surface of a vehicle. Effect of incoming fluid velocity, angle that the inclined surface makes with the horizontal plane and angle of impinging jet on heat transfer will be examined. The results are correlated in terms of governing dimensionless parameters. The end-result will be a numerically-based correlation that is capable of predicting heat transfer on an inclined surface subject to impinging airflow.Copyright