Woodruff School of Mechanical Engineering

Mechanical Engineering Seminar

Title:

SUPERSONIC EJECTOR TECHNOLOGY FOR SOLAR AIR CONDITIONING: NUMERICAL SIMULATION AND EXPERIMENTAL RESULTS AT THE COMPONENT AND SYSTEM SCALE

Speaker:

Prof. Yann Bartosiewicz

Affiliation:

Université catholique de Louvain

When:

Thursday, April 19, 2012 at 11:00:00 AM

Where:

MRDC Building, Room 4211

Host:

Dr. Srinivas Garimella
srinivas.garimella@me.gatech.edu
404-894-7479

Abstract

This talk will focus on supersonic ejector technology research and its use to achieve air-conditioning from low grade energy sources. An ejector, also called a jet-pump, is a simple device that consists of two coaxial nozzles without any moving mechanical parts. Such a device could be used to draw fluid from a low-pressure region to a higher-pressure region as a pump or a compressor would do. However, this compression occurs solely from an exchange of energy between two streams, namely the primary stream issued from the center nozzle at a high energy level and the secondary stream to compress. The process of energy exchange is nevertheless very complex because it is done through a turbulent transonic shear layer in the case of a supersonic ejector. This presentation will cover the different aspects of the research at the ejector scale as well at the system scale. At the ejector scale, the different numerical models and results used to predict the ejector operation and internal flow features will be discussed. Experimental work will be shown to support the validation of such models. At the system scale, system design, setup, and results from a full air-conditioning cycle built in the TFL lab will be presented. Finally, in order to emulate the operation of this stand under realistic conditions, a dedicated model has been setup, including the operation map of the lab prototype. This emulator includes a dynamic model of a house to be defined by the user (geographic location, walls composition, equipment, etc.) allowing transient simulation of seasonal behavior of a solar air-conditioning ejector-based system. The results of this model will be presented with an analysis of ejector system operating characteristics.


Biography

Prof. Yann Bartosiewicz graduated in France at the Polytechnic National institute of Grenoble in fluid mechanics and transport phenomena, with a major in numerical simulation of turbulent flows. He obtained his PhD in early 2003 from Université de Sherbrooke, Canada where he worked on in numerical simulation of supersonic plasma jets under thermodynamic non-equilibrium conditions. Prof. Bartosiewicz was a scientist at Natural Resources Canada until the end of 2005 where he developed models for supersonic ejectors working with different refrigerants to improve refrigeration cycles. He is currently a Professor in Belgium, at Université catholique de Louvain (UCL) where he teaches thermodynamics, thermal cycles and advanced nuclear thermal hydraulics. His research is performed within the Institute of Mechanics, Materials, and Civil engineering (iMMC). His current activities cover energy systems with a focus on energy efficiency as well as two-phase chocked flows and heat transfer under low Prandtl conditions (liquid metals).