Investigation Of Pressure Drop And Dynamic Instabilities In Two Phase Flow

Zweiphasenströmungen, insbesondere Wasser/Dampf-Strömungen, sind für die Auslegung und den Betrieb thermohydraulischer Systeme nach wie vor von großem Interesse. Diese Arbeit befasst sich mit der Untersuchung des Druckverlustes und dynamischer Instabilitäten (hier Dichtewellenoszillationen) in Wasser/Dampf-Strömungen mittels zweier unterschiedlicher Ansätze unter praxisnahen Bedingungen. Zum einen wird ein Versuchsstand entwickelt, aufgebaut und in Betrieb genommen, um mit diesem entsprechende Versuche an einem Verdampferrohr durchzuführen. Zum anderen werden dynamische Simulationen mit einem homogenen („mixture flow“) und einem heterogenen („two-fluid“) Strömungsmodell durchgeführt und miteinander und mit den Messdaten verglichen. Die experimentellen und numerischen Ergebnisse lassen sich schließlich in dimensionslosen Stabilitätskarten zusammenfassen, welche die Betriebsgrenzen beschreiben, bei denen Dichtewellenoszillationen in thermohydraulisch ähnlichen Systemen auftreten können.

Heat transfer enhancement in single-phase and two-phase flow heat exchangers in important in such industrial applications as power generating plant, process and chemical industry, heating, ventilation, air conditioning and refrigeration systems, and the cooling of electronic equipment. Energy savings are of primary importance in the design of such systems, leading to more efficient, environmentally friendly devices. This book provides invaluable information for such purposes.

This book presents selected papers from the 7th International Conference on Advances in Energy Research (ICAER 2019), providing a comprehensive coverage encompassing all fields and aspects of energy in terms of generation, storage, and distribution. Themes such as optimization of energy systems, energy efficiency, economics, management, and policy, and the interlinkages between energy and environment are included. The contents of this book will be of use to researchers and policy makers alike.

The study of multiphase flows is of utmost interest for engineers who are more or less inevitably faced with them when handling various industrial processes or when dealing with environmental problems such as the dispersion of pollutants. It is also a large kingdom assembling many beautiful and weird landscapes in which wandering researchers may be caught by the fascination of precious stones or mysterious insets to deep and obscure caverns. Unfortunately, it is also an historically disconnected field of research, as testified by any textbook contents or by the scientific programs of conferences devoted to multiphase flows. For instance, is there a relation between fluidization and the study of interfacial waves, or between the behaviour of an annular film of liquid and the one of a free surface heated from below? The answer is indeed: yes. To help reveal some unity behind the avatars of multiphase flow behaviours, it has been decided to focus the interest on the instability phenomena. This book therefore provides the reader with most of the papers which have been accepted and/or presented at the international symposium on "instabilities in multiphase flows" held at the National Institute for Applied Science (INS A) in Rouen, France, from the 11 th of May to the 14th of May 1992. The topic of the conference has produced a strong emphasis on instability theory and nonlinear dynamics, including chaotic phenomena.

This book provides a compilation of important optical techniques applied to experiments in heat and mass transfer, multiphase flow and combustion. The emphasis of this book is on the application of these techniques to various engineering problems. The contributions are aiming to provide practicing engineers, both in industry and research, with the recent state of science in the application of advanced optical measurements. The book is written by selected specialists representing leading experts in this field who present new information for the possibilities of these techniques and give stimulation of new ideas for their application.

Refrigeration plays a prominent role in our everyday lives, and cryogenics plays a major role in medical science, space technology and the cooling of low-temperature electronics. This volume contains chapters on basic refrigeration systems, non-compression refrigeration and cooling, and topics related to global environmental issues, alternative refrigerants, optimum refrigerant selection, cost-quality optimization of refrigerants, advanced thermodynamics of reverse-cycle machines, applications in medicine, cryogenics, heat pipes, gas-solid absorption refrigeration, multisalt resorption heat pumps, cryocoolers, thermoacoustic refrigeration, cryogenic heat transfer and enhancement and other topics covering theory, design, and applications, such as pulse tube refrigeration, which is the most efficient of all cryocoolers and can be used in space missions.