The characteristics of turbulent diffusion of jet in coaxial flow excited periodically were intensively investigated.
Hot-wire technique was used to measure the fluctuation of concentration in binary gas mixture and instantaneous Schlieren photographs were taken for visualization of flow pattern.
From the result of the work, the mean concentration of the inner helium jet is not nearly affected at the change of momentum transfer of the outer flow field, on the while the fluctuation of concentration is quite affected and the effects mostly appear at the initial and transition region of the inner jet.
