Flow Visualization of Coaxial Impingement of Opposing Jets in Mixing Chamber

Abstract

This paper presents flow patterns of coaxial impingement of opposing jets, which are modeled on the jets in the mixing chamber of reaction injection molding. The flow visualization is carried out by the hydrogen bubble method by using water as working fluid for the jet Reynolds number from 50 to 1700.
The results show that the flow patterns of the impingement are approximately classified according to the Reynolds numbers as follows.
(1) Re ?? 200 : The flow is stable, as the flow downstream of the impingement surface has no obvious fluctuation.
(2) 200 ?? Re ?? 500 : The impingement surface is unstable, as it may be traveled by a trivial disturbance.
(3) Re ?? 500 : The flows upstream and downstream of the impingement surface have some fluctuation, though the impingement surface is almost fixed.