2014 年 62 巻 1 号 p. 15-23
In STOL, it is a critical factor to maintain lifting force stably at low speed. For this purpose, a jet from the engine flows along the wing surface to create a large uptrend centrifugal force which yields an additional uplift force on the wing. In this research, numerical calculation using the Large Eddy Simulation method is performed to find out about this special characteristic of a jet under the influence of inertial forces. It is observed that the secondary flow appears within the jet and its vicinity. The pressure gradient normal to the wing surface, which creates the lift force, is increased by the addition of the jet. It is also observed that the jet center moves relatively to the reference frame adopted in the simulation, and the direction of the movement slightly deviates from the centrifugal force if the jet is swirling. At the initial time, the mean flow is distributed axisymmetrically, and it is shown that the inhomogeneous distribution of Coriolis force, which is due to the swirl, causes most part of the jet center's spanwise movement. In the course of time, however, the influence of advection in the plane perpendicular to the jet magnifies the spanwise movement.