بررسي تجربي و شبيه سازي عددي جريان در لوله ورتكس

چكيده انگليسي :

100 Experimental Investigation and Numerical Simulation of Flow in the Vortex Tube Jaber Sadeghi Seraji j sadeghi@me iut ac ir Date of Submission 9 14 2014 Department of Mechanical Engineering Isfahan University of Technology Isfahan 84156 83111 IranDegree M Sc Language FarsiSupervisor Mohsen Davazdah Emami mohsen@cc iut ac irAbstract Ranque Hilsch vortex tube is a simple mechanical device that has no moving components and is used aspart of the equipment in the refrigeration system where a high pressure fluid is entered the vortex tubethrough the entrance nozzles and splits into two flows with lower and higher temperature compared to inlettemperature and in this way temperatures up to 40 C are achievable Vortex tube has broad applications asspot cooling and spot heating in the industry such as cool plastic injection moulds dehumidify gasoperations cool heat seal operations cooling of control cabinet electrical enclosures cooling of cameralenses setting solders and adhesives and dry ink on labels and bottles Although many experimental studieshave been done on the performance of vortex tube the physics of the flow and mechanism of temperatureseparation phenomenon of gas or vapor passing through the vortex tube are not well understood because ofcomplexity of the flow and incompatibility of experimental results The first goal of this thesis is to recordcold and hot temperatures triggered by temperature separation phenomenon versus cold fractionexperimental investigation of one type of vortex tube experimental equipment R433 made by P A Hiltoncompany in England Experimental results include cold and hot exit static temperatures diagrams based oncold fraction and cold exit pressure diagram versus cold fraction using cold and hot exit static temperatures Heat pump and cooler coefficient of performance diagrams of vortex tube and also isentropic efficiency arepresented according to available equations Uncertainty of experimental results is calculated usingexperimental Holman relation and is illustrated as error bars in the former diagrams Then usingcomputational fluid dynamics approaches available in ANSYS CFX 14 5 software numerical simulation ofsteady compressible and three dimensional flow in the vortex tube has been done by utilizingcomputational structural and hexahedral grid Appropriate boundary conditions are applied in the numericalsimulation corresponding to the experimental conditions with the exception of hot exit which has been setsuch that the operation of flow control valve could be assimilated Several turbulence models such as thestandard k model k and SST k have been used Finally hot and cold exit static temperatures heatpump and cooler coefficient of performance and isentropic efficiency diagrams derived from numericalsimulation have been compared to the ones based on experimental results In addition results of numericalsimulation are presented as contours of static temperature stagnation temperature density mach number velocity distributions and stream lines focused on position of stagnation point and the zone which secondaryflow forms Key wordsVortex Tube Experimental Investigation Computational Fluid Dynamics TemperatureSeparation Cold Fraction Standard k k SST k Model

صادقي سراجي، جابر

بررسي تجربي و شبيه سازي عددي جريان در لوله ورتكس

ديناميك سيالات محاسباتي , جدايش دما , كسر سرد , مدل K-ω , SST K-ω