Particle image velocimetry (PIV) was used for learning the 5mm diameter warped hole flow field in jet-in-crossflow. The result shows that: the jet angle differs from the warped hole angles

the larger of the warped hole angle means the larger jet angle; there will be a useful parameter named effective diameter from the experiment data. Jet flow trajectory curves were fitted in condition of two types of velocity

four different warped hole angles and three tunnels with different depth. The curve is well fitted with the real jet flow

contributing to the future flow field design in micro combustors or other small tunnels.