ACRL - On-Going Research and Results

Ongoing Research

  • Infiltration rates measurement (by CFD and also experimental tracer gas technique). Tests are performed for hundreds of permutations of some of the most important non-dimensional variables that are believed to significantly impact the infiltration rates.
  • Study the structure (by DPIV) of the scenarios that result in the minima by carefully studying the mean velocities, fluctuating components of the velocities, vorticities, and shear stresses at the shear layer and near the impingement region
  • Flow passing over a cavity with a flow sink in the downstream.

Sample of Results

Variation of the concentration of the tracer gas (CO2) in air, from the beginning of the injection to the stop of the data logging.

The measured concentrations are at the discharge of the air curtain (DAG), return duct (RAG), and room. The calculated non-dimensional infiltration rate has been plotted in green.

This figure presents the experimental infiltration rate data for different offset angles (a) and Reynolds numbers, at constant discharge angle of -5º, height-to-discharge width ratio of 8, and back panel flow of about 33% of the total flow rate.

CFD simulation of POCAC for a=0, ß=0, H/w=16, Re=2,200 and zero back panel flow. The left figure depicts the streamlines in and around the display case prototype, and the right figure presents the mass concentration contours of CO2, the tracer gas. It is evident that the higher concentration of the tracer gas (representing the colder air), is near the floor (a: offset angle between the DAG and RAG, ß: throw angle at the discharge, H: the opening height, w: width of the DAG, Re: Reynolds number at the DAG)

DPIV results of streamlines of air curtain, and the entrained air by the air curtain in an open refrigerated display case.