Date of Graduation

12-2025

Document Type

Thesis

Degree Name

Bachelor of Science in Chemical Engineering

Degree Level

Undergraduate

Department

Chemical Engineering

Advisor/Mentor

Tom Spicer

Committee Member

Heather Walker

Second Committee Member

Jamie Hestekin

Third Committee Member

Keisha Walters

Abstract

Atmospheric releases of heavier-than-air gases pose acute near-field hazards in low wind, yet the near-source behavior of vertical dense-gas jets in still air is sparsely documented. This thesis demonstrates a repeatable laboratory method for measuring the initial and steady-state rise heights of a carbon dioxide (CO₂) jet issued vertically from a floor nozzle in the CHRC ultra-low-speed wind tunnel under still-air conditions. Controlled mixtures (pure CO₂, 50/50 CO₂-air, 25/75 CO₂-air) were released at four flow rates (75, 100, 125, 150 LPM) with five repeats per condition. A fixed camera and tape-measure scale enabled video extraction of jet height using Kinovea video analysis software. A convergence study established the sample counts needed to obtain stable steady-state means for each mixture. Across all compositions, the initial peak height exceeded the steady height and both increased with less dense concentrations. For a fixed density, increasing the flow rate of the release produced higher initial and steady-state heights. The separation between initial and steady-state heights generally widened with increasing flow. These results provide validation for the setup and method, informing future work to create still air datasets of vertical dense-gas rise behavior that can support model selection, parameterization, and emergency-response guidance, and they outline a path to larger test matrices, automated edge detection, and extension to crossflow jets in moving air.

Keywords

Dense-gas dispersion; Negatively buoyant vertical jets (fountain effect); CO₂ pipeline rupture—near-field source characterization; Ultra-low-speed wind tunnel experiments; Plume rise height (initial vs steady-state); Video-based plume measurement

Download

Share

COinS