수축부 길이 변화에 따른 풍동 내부유동장 특성에 대한 수치해석

Abstract

The steady-state, incompressible and three-dimensional numerical analysis was carried out to investigate the internal flow field characteristics of wind tunnel according to the change of contraction length. This study used a realizable k-ε turbulence model. As a result, regardless of the contraction lengths, the minimum value of the axial mean velocity component at the entrance of the plenum chamber is increased through the contraction and has the maximum value in the test section. When the flow passes through the inner space of the analytical models, the average pressure and axial force due to the surface pressure acting at the inlet of the plenum chamber is the smallest at the contraction length of 1,000 mm, but the axial force due to the surface stress increases as the contraction length increases. The maximum turbulent kinetic energy in the test section decreases as the contraction length increases. Comprehensively, it can be concluded that the contraction length of 1,000 mm at the contraction area ratio of 9:1 is the best choice for wind tunnel selection with superior performance.