Dimensions optimization design of a low-speed wind tunnel for an expanded test section with limited overall space

In this paper, a novel multi-objective optimization framework is proposed for the global dimensions of the lowspeed wind tunnel supported by the Belt and Road Joint Laboratory (BRJL-LWT). Three indexes are considered in the process: the flow quality index, the total pressure loss index and the test section volume index. The flow quality is taken as a constraint on the aerodynamic requirements, while pursuing a larger test section space and lower total pressure loss. A multi-objective optimization algorithm is adopted as the solver for the optimization process at four initial flow velocities. The results show that the flow quality of the optimized large test section fully meets the target requirements for structure fluid testing. The total pressure loss index is inversely proportional to the test section volume index for all initial flow velocities. Finally, the optimal BRJL-LWT dimensions are determined and the optimal BRJL-LWT model is developed. The fluid analyses are performed to assess the flow uniformity and turbulence intensity of the fluid within the test section. This optimization framework not only enables the designed wind tunnel to produce the required flow field conditions, but also makes efficient use of the test section space and reduces the facility's operational energy consumption, which significantly extends the applicability of the wind tunnel design.