抄録
Turbulent energy transport mechanism involved with large-scale coherent structures in a self-similarity region of a turbulent plane jet is investigated experimentally. First, simultaneous multipoint measurements of two velocity components and pressure are performed by using the “combined probe” which consists of a pressure probe and an X-type hot-wire probe. Then, Proper Orthogonal Decomposition (POD) is applied to both velocity and pressure fields to extract the coherent structure in the jet. Further, the complementary techniques of POD and Linear Stochastic Estimation (LSE) are used to reconstruct spatiotemporal velocity and pressure fields of the dominant POD mode. As a result of reconstruction, we observe the coherent structure with the counter-rotating vortices staggering with respect to the jet centerline: it contains approximately 42 % of the total energy. Finally, the turbulent energy transport is evaluated by using reconstructed velocity and pressure data. The results show that the production and pressure diffusion of the turbulent energy in the jet are mainly caused by the coherent structure.
