EXPERIMENTAL INVESTIGATION OF DOUBLE SELF-IMPINGING JETS WITH HIGH REYNOLDS AND WEBER NUMBERS

Self-impinging liquid jets can provide efficient atomization, which is utilized, inter alia, in rocket engines. The following research presents an analysis of structures formed by the collision of two jets with an impingement angle of 30° under relatively high Reynolds and Weber numbers. Structures formed by two symmetrical water columns impinging at a low angle were investigated experimentally using a high-speed camera and global illumination. It aimed at verifying within what angles (measured in two perpendicular directions) the liquid is distributed depending on the jets' Reynolds and Weber numbers. The results revealed that the spray cloud is highly affected by the ruptures of the liquid sheet, which leads to its immediate disintegration for high Reynolds and Weber numbers of jets. Increased dimensionless numbers resulted in a wider spray angle observed in a normal direction to the plane of jets. At the same time, the angle viewed parallel to the jets' plane decreased, indicating a possible transition from a planar to a conical spray shape. When these two dimensionless numbers are high enough, intensive atomization of wide, symmetrical spray can be achieved even under low injection pressures (≤ 1 MPa).