I am a new user of the Flow component to SolidWorks. Irecently purchased Flow to reverse engineer a product design thatdid not perform as expected. And, of course, to improve our designinsight in the future.
The specific project was a helical oil separator which is expectedto separate gaseous ammonia from liquid mineral oil as a componentto a refrigeration system. The velocity profiles computed by Flowand the particle studies seem to be realistic.
However, the actual thermal surface plots on the vessel are instark disagreement with the Flow thermal predictions. This leads toa few questions that some of you out there might have insight:
1. Does Flow calculate turbulent vs. laminar flow based upon fluidvelocity, tempertature, etc. or is this an input criteria? Withvelocities of NH3 gas of about 300 fps max. I would expect the flowto not be turbulent, and thus the heat exchange with the NH3 gasand the vessel and the ambient would be calculated upon thetemperature gradient of the gas at a somewhat low velocity relativeto the vessel wall. There shoud be a temperature gradient in thegas flow at this low velocity, which does not seem to be modeledcorrectly by Flow.
2. Is the thermal properties of the particles (mineral oil liquid)taken into account in the thermal calculations?? There is a largedifference between the specific heat of gas and liquid. The thermalproperties of the mass flow of the liquid is way more significantthan the thermal properties of the vapor. But the Flow calculationseems to be solely based upon the vapor. Am I missing the methodwherein the thermal properties of the particle (liquid) mass flowis included in the calculation?
In my reality, the temperature drop (inlet to outlet) on thesurface of the oil separator was about 5 degrees F. The Flowprediction was about 35 degrees F.
Any insight is greatly appreciated.
David PaulsonSolidworksFlow Simulation
The specific project was a helical oil separator which is expectedto separate gaseous ammonia from liquid mineral oil as a componentto a refrigeration system. The velocity profiles computed by Flowand the particle studies seem to be realistic.
However, the actual thermal surface plots on the vessel are instark disagreement with the Flow thermal predictions. This leads toa few questions that some of you out there might have insight:
1. Does Flow calculate turbulent vs. laminar flow based upon fluidvelocity, tempertature, etc. or is this an input criteria? Withvelocities of NH3 gas of about 300 fps max. I would expect the flowto not be turbulent, and thus the heat exchange with the NH3 gasand the vessel and the ambient would be calculated upon thetemperature gradient of the gas at a somewhat low velocity relativeto the vessel wall. There shoud be a temperature gradient in thegas flow at this low velocity, which does not seem to be modeledcorrectly by Flow.
2. Is the thermal properties of the particles (mineral oil liquid)taken into account in the thermal calculations?? There is a largedifference between the specific heat of gas and liquid. The thermalproperties of the mass flow of the liquid is way more significantthan the thermal properties of the vapor. But the Flow calculationseems to be solely based upon the vapor. Am I missing the methodwherein the thermal properties of the particle (liquid) mass flowis included in the calculation?
In my reality, the temperature drop (inlet to outlet) on thesurface of the oil separator was about 5 degrees F. The Flowprediction was about 35 degrees F.
Any insight is greatly appreciated.
David PaulsonSolidworksFlow Simulation
