Thermal analysis of sealed enclosure for over the ocean application [marine applications]

RF communication sub-systems, used in marine applications, are deployed on the mast of vessels to achieve reliable reception of microwave signals. They are housed in sealed enclosures to protect against the corrosive sea environment. Natural convection is the preferred method of cooling in such enclosures for ease of maintenance. Conducting verification tests on such enclosures in the actual environment is difficult due to logistic problems. Also, laboratory test conditions may not be representative of the actual operating scenario. This can be avoided by numerical analysis of the sub-system thermal model in the intended environment, resulting in prediction of the temperature. This paper demonstrates detailed analysis of a typical system for marine applications. The unit was modeled and transient analysis was conducted using CFD techniques for various sea ambient and sea states. The analysis results show that the component temperatures are lower in the simulated sea environment and thermal shut off may not take place, even though it has failed previously during verification tests under lab conditions. This case study demonstrates that CAD simulation and CFD analysis can provide diagnostic information and guide the development of a good cooling solution with less "cut and try" effort.