Study of Electrostatic Effects on Condensing Heat Transfer
Report Number: AFFDL TR 65-51
Author(s): Choi, Harry Y., Reynolds, John M., III
Corporate Author(s): Tufts University and Massachusetts Institute of Technology
Laboratory: Air Force Flight Dynamics Laboratory
Date of Publication: 1965-05
Pages: 138
Contract: AF 33(657)-10908
DoD Project: 6146
DoD Task: 614615
Identifier: AD0467747
Abstract:
A study program is presented on the effects of strong electric fields on condensation heat transfer and two-phase flow. It has been confirmed that significant changes in the flow regimes and heat transfer are possible with negligible electrical power expenditure. Over 100 per cent increase in heat transfer has been attained with pressure drop increases which are of the order of 15 per cent in the annular flow regime. These investigations were performed on two separate apparatus: one at Tufts University in which heat transfer phenomena in condensation were investigated and one at the Massachusetts Institute of Technology in which hydrodynamic phenomena in two-phase flow were studied. Results show that the slug flow regime is substantially suppressed. In essence, slug flow occurs only in the region of very low gas flows in which the system is almost entirely gravity dependent. The increase in heat transfer rates is gradual up to a certain threshold value of the applied voltage; beyond this value, the increase is steep. Some progress has been made in analytical and physical modeling of the phenomenon both from the viewpoint of determining pressure drop and heat transfer and of aiding in the determination of the fluid configuration at the heat transfer surface.
Provenance: Lockheed Martin Missiles & Fire Control
Author(s): Choi, Harry Y., Reynolds, John M., III
Corporate Author(s): Tufts University and Massachusetts Institute of Technology
Laboratory: Air Force Flight Dynamics Laboratory
Date of Publication: 1965-05
Pages: 138
Contract: AF 33(657)-10908
DoD Project: 6146
DoD Task: 614615
Identifier: AD0467747
Abstract:
A study program is presented on the effects of strong electric fields on condensation heat transfer and two-phase flow. It has been confirmed that significant changes in the flow regimes and heat transfer are possible with negligible electrical power expenditure. Over 100 per cent increase in heat transfer has been attained with pressure drop increases which are of the order of 15 per cent in the annular flow regime. These investigations were performed on two separate apparatus: one at Tufts University in which heat transfer phenomena in condensation were investigated and one at the Massachusetts Institute of Technology in which hydrodynamic phenomena in two-phase flow were studied. Results show that the slug flow regime is substantially suppressed. In essence, slug flow occurs only in the region of very low gas flows in which the system is almost entirely gravity dependent. The increase in heat transfer rates is gradual up to a certain threshold value of the applied voltage; beyond this value, the increase is steep. Some progress has been made in analytical and physical modeling of the phenomenon both from the viewpoint of determining pressure drop and heat transfer and of aiding in the determination of the fluid configuration at the heat transfer surface.
Provenance: Lockheed Martin Missiles & Fire Control