Pressure effect on the flow fields and the Reynolds stresses in a bubble column

The hydrodynamics of bubble columns operated at pressures up to 7.0 MPa are investigated using a laser Doppler velocimetry system. Laser Doppler veloc imetry is a noninvasive optical technique, which is used to conduct in situ measurements of velocity, with high spatial resolution, fast dynamic respo nse, and the ability to detect flow. The axial and tangential velocities an d the Reynolds shear and normal stresses are analyzed and discussed in rela tion to large-scale structures present in the flow. This study demonstrates the significance of the pressure effect on the flow field in bubble-column systems.