Computational Analysis
Computational Fluid Dynamics (CFD)
Computational Fluid Dynamics (CFD) and thermal analysis are performed using standard edition of the COSMOS FloWorks™ software package. This package is fully embedded in SolidWorks, which makes transition from device assembly model to calculation seamless.
Target Heat Transfer and Flow Modeling.
Table 1. General FloWorks™ Settings
| AnalysisType | Closed Cavities |
Fluid |
Solids |
Wall Condition |
| Internal Flow | Exclude cavities without flow conditions | Water |
Heat Exchanger – Copper; Rest parts -insulators |
Adiabatic; Zero roughness |
Modeling results are verified using the heat energy balance method. The accuracy of a heat balance calculation is limited to averaging bulk temperature and velocity method at the outlet by the FloWorks™ software. A fluid velocity plot at the apex shows a “dead zone” with almost zero velocity on the conical surface of the heat exchanger. This is the effect of a positive pressure gradient that is created due to a direct “hit” of the fluid stream into the wall and restricted flow from the bottom of narrow channels at their ends.
Figures 1 and 2 present absolute fluid velocity in the channels and a 3D plot, respectively. As can be seen from these plots, there is almost zero fluid velocity around the conical surface. Therefore, the heat transfer coefficient in this area is extremely low, which leads to a high temperature in the target apex area. As a result, the water temperature in this area is also high (310K), which, in combination with low static pressure, could lead to nucleate boiling conditions on the conical surface followed by film boiling with low heat flux transfer and target melting.
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| Fig-1 Absolute Velocity Distribution | ||
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| Fig-2 Absolute Velocity Distribution at Apex | ||
Stress Analysis