Inverse design of the thermal environment in an airliner cabin by use of the CFD-based adjoint method

• The adjoint method was applied to inverse design of thermal environment.
• The design method is innovative for thermal environment.
• The design used the mixed and displacement ventilation systems as examples.
• The design process can identify the optimal variables in less than 10 design cycles.

The current thermal environments in airliner cabins may not provide satisfactory comfort levels, and the design of these environments should be improved. This study aimed to design a desirable thermal environment for a single-aisle airliner cabin and used the CFD-based adjoint method to find the optimal design variables of air supply locations, size, and parameters. The design variables are used as the boundary conditions for solving the Navier–Stokes equations. By setting the occupant region as the design domain with a minimal predicted mean vote for thermal comfort, this study aimed to determine the corresponding air supply conditions for mixing and displacement ventilation systems under summer and winter conditions. The results show that it is possible to find the optimal air supply conditions in fewer than 10 design cycles if the initial conditions for design variables are provided within a reasonable range. This design method has a high computing efficiency as it takes one hour for a design cycle using a 16-core cluster. In addition, the results show that a displacement ventilation system provides a better thermal comfort level than a mixing ventilation system.