Development and evaluation of a device for measurement of superficial void fraction during two-phase flow external to tube bundles

• Grant number: 12/22610-2
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: March 01, 2013
• End date: February 28, 2014
• Field of knowledge: Engineering - Mechanical Engineering - Transport Phenomena
• Principal Investigator: Gherhardt Ribatski
• Grantee: Rodrigo Takashi Endoh
• Host Institution: Escola de Engenharia de São Carlos (EESC). Universidade de São Paulo (USP). São Carlos , SP, Brazil

Abstract

Void fraction is an important parameter during two-phase flows which is directly related to the gravitational, acceleration, and frictional parcels of the pressure drop. Void fraction also affects the flow pattern and heat transfer coefficient. The characterization of the void fraction is also essential in the analysis of safety in heat exchangers due to the possibility of wall drying out and in the analysis of dynamic aspects in tube bundles involving excitation and damping mechanisms of the induced flow vibrations. The present research proposal concerns the development and evaluation of a device for superficial void fraction measurements through electrical capacitive sensoring applied to tube bundle external flows. It is intended to evaluate the sensoring system for mock configurations which will simulate bubbly and annular flows. The research will be developed in the Heat and Mass Transfer Group of the Mechanical Engineering Department at São Carlos School of Engineering - USP. The proposed measurement device will be used in the doctoral research of Fabio Toshio Kanazawa (FAPESP Grant number 2010/20670-2) which study is focused in the investigation flow patterns, void fraction, and pressure drop during two-phase flows external to tube bundles. This study has also the support of CNPq through a research grant number 481044/2010-8.(AU)