{"title":"Pressure Induced Isenthalpic Oscillations with Condensation and Evaporation in Saturated Two-Phase Fluids","authors":"Joel V. Madison, Hans E. Kimmel","country":null,"institution":"","volume":45,"journal":"International Journal of Physical and Mathematical Sciences","pagesStart":1235,"pagesEnd":1241,"ISSN":"1307-6892","URL":"https:\/\/publications.waset.org\/pdf\/9459","abstract":"Saturated two-phase fluid flows are often subject to\r\npressure induced oscillations. Due to compressibility the vapor\r\nbubbles act as a spring with an asymmetric non-linear characteristic.\r\nThe volume of the vapor bubbles increases or decreases differently if\r\nthe pressure fluctuations are compressing or expanding;\r\nconsequently, compressing pressure fluctuations in a two-phase pipe\r\nflow cause less displacement in the direction of the pipe flow than\r\nexpanding pressure fluctuations. The displacement depends on the\r\nratio of liquid to vapor, the ratio of pressure fluctuations over average\r\npressure and on the exciting frequency of the pressure fluctuations.\r\nIn addition, pressure fluctuations in saturated vapor bubbles cause\r\ncondensation and evaporation within the bubbles and change\r\nperiodically the ratio between liquid to vapor, and influence the\r\ndynamical parameters for the oscillation. The oscillations are\r\nconforming to an isenthalpic process at constant enthalpy with no\r\nheat transfer and no exchange of work.\r\nThe paper describes the governing non-linear equation for twophase\r\nfluid oscillations with condensation and evaporation, and\r\npresents steady state approximate solutions for free and for pressure\r\ninduced oscillations. Resonance criteria and stability are discussed.","references":null,"publisher":"World Academy of Science, Engineering and Technology","index":"Open Science Index 45, 2010"}