|Book Series (78)||
|Mechanical and process engineering||765|
|Mining and metallurgy||29|
|Architecture and civil engineering||63|
5. Auflage bestellen
|ISBN-13 (Hard Copy)||9783736994935|
|Place of Dissertation||Bremen|
Manufacturing and production engineering
|Keywords||Microgravity, two-phase flow, heat transfer, mass transfer, CFD, CHT, experimental work, cryogenic fluids, free surface reorientation|
Two-phase flow with a free surface, non-isothermal boundary conditions and heat and mass transfer over the free surface must be understood for a save operation of cryogenic upper stages with restart capability. This work is a foundational research carried out with numerical and experimental means.
A mathematical and numerical model were developed that allow to describe such systems under varying gravity levels. The reorientation of cryogenic parahydrogen upon a sudden gravity step reduction was investigated experimentally using the drop tower at ZARM, University of Bremen. Influencing the motion and final shape of the free surface could be realized with a precisely defined wall temperature gradient.
Heat and mass transfer over the free surface in a microgravity environment could be investigated numerically based on the experimental results of the SOURCE-II sounding rocket experiment. A transient simulation was carried out to study the coupled system between superheated container wall, subcooled liquid, free surface configuration and three-phase contact angle.