Analysis of flow structure in a helicopter cabin to improve the thermal comfort using computational fluid dynamics modeling

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2018
Şahin, Doruk
Proper distribution of conditioned air inside the cabins of passenger transportation type aircrafts is crucial in terms of passengers’ comfort. Low air velocities may cause passengers to feel stuffy whereas high velocities may create disturbance. Moreover, satisfying uniform temperature distribution inside the cabin is also crucial for the passenger comfort. High temperature variation inside the cabin results in feeling of discomfort. In this thesis, computational fluid dynamics (CFD) models are developed using ANSYS FLUENT to investigate thermal comfort level of the passengers in a newly designed passenger transportation helicopter. The desired air velocities in the vicinity of the faces of passengers are determined by utilizing SAE ARP292, ASHRAE 161-2013 and ASHRAE 161-2007. Moreover, in addition to air velocity, effective distribution of the personalized air flow around the faces of passengers is also considered. On the other hand, SAE ARP292 is used to determine the temperature related comfort parameters. For the analyses, a turbulence model anticipated as suitable for cabin type flows is selected and the competence of its performance is confirmed by the experimental and numerical results available in the literature. The results reveal that the existing design of personalized air distribution system is inadequate for creating comfortable environment to passengers. For the purpose of enhancing thermal comfort of the passengers, an iterative procedure is followed to redesign personalized air distribution system by evaluating the results of numerical simulations in terms of thermal comfort levels. By the present thesis study, by redesigning personalized air inlets, adjusting their locations and proposing a flow rate ratio between personalized and main inlet flows, an improvement has been shown up in terms of thermal comfort levels of the passengers. The new design provides air velocities between the designated comfort range and effective distribution of the personalized air flow around the faces of passengers. Moreover, the temperature distribution inside the cabin becomes more uniform by the new design.
Citation Formats
D. Şahin, “Analysis of flow structure in a helicopter cabin to improve the thermal comfort using computational fluid dynamics modeling,” M.S. - Master of Science, Middle East Technical University, 2018.