Flow Prediction and Fluctuation-sensitivity Investigations for Quasi-steady Shear Driven Condensing Flows in Milli-meter to Micro-meter Scale Two-Phase Systems

Michigan Technological University, Houghton MI

Investigators

Abstract

1033591 Narain This research will aid the development of microscale thermal systems that involve liquid-vapor phase change. To achieve desired system performance, it is often the case that shear-driven quasi-steady condensing flows must be made to behave in a predictable and maintainable fashion. Reliable flow prediction capability is therefore needed for millimeter-to-micrometer scale condensers. Intellectual Merit: This research seeks to quantify the fluctuation energy transfer mechanisms to and from a condensing flow that might cause significant transient behavior within and outside of a microscale condenser. Experiments involving three different test sections (horizontal gaps or tubes with characteristic dimensions of 200 micrometers to 2 millimeters) in an instrumented flow-loop facility will lead to measured quantitative information on how a small-scale condenser responds - dynamically and thermally - to fluctuation energy transferred through its inlet and outlet. Quantities to be measured include heat transfer coefficients, pressure drops, and other important criteria that are crucial for successful design and operation. The experimental study will be augmented with simulations to generate a predictive capability applicable to a wide array of geometries and various condensing surface temperature conditions. Broader Impacts: Flow boiling and condensation has promising potential to meet high heat flux needs in many applications. This research will enable a more quantitative prediction of flow and heat transfer in small scale condensers. The research will involve graduate students and undergraduate students recruited from underrepresented groups.