UFR 1-07 Test Case
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Unsteady Near-Field Plumes
Underlying Flow Regime 1-07
Test Case Study
Brief Description of the Study Test Case
- A summary of the boundary conditions is shown in Figure 8.
- A gas mixture mainly composed of helium is discharged through a circular orifice into ambient air.
- The gas is composed of 96.4% helium, 1.7% acetone and 1.9% oxygen by volume.
- The molecular weight of the gas released is 5.45 g/mol ±2.7%.
- The mixture is discharged at a temperature of THe = 11°C ±3°C and the air is at Tair = 13°C ±3°C.
- The circular plume source has diameter, D = 1 metre.
- The helium is discharged at a Reynolds-averaged velocity V0 = 0.325 m/s ±1.3% and a Favre-averaged velocity of approximately 0.339 m/s.
- The flow through the orifice is laminar.
- The ambient pressure is 80.9 kPa ±0.4 kPa.
- The measurements include:
- Time-history of vertical velocity at a point 0.5 m from the centreline and 0.5 m above the inlet, used to estimate the puffing frequency
- Measurements on a vertical plane through the plume from the plume source to a distance of one orifice diameter of:
- Reynolds-averaged and Favre-averaged mean axial and radial velocities
- Reynolds-averaged and Favre-averaged shear stresses, normal stresses and turbulent kinetic energy[1]
- Favre-averaged helium concentrations
- Movies of helium concentration and velocities
- Profiles of the mean and RMS velocities, and mean and RMS helium concentrations at six measurement positions (0.1, 0.2, 0.3, 0.4, 0.5 and 0.6 m downstream of the plume source)
Item 1 is available in the O‘Hern et al. [4] paper, Items 2 and 3 can be obtained by contacting the authors of the study[2]. and Item 4 is presented by Chung & Devaud [39].
Test Case Experiments
CFD Methods
Footnotes
- ↑ Only velocities parallel to a two-dimensional plane were recorded. The turbulent kinetic energy, k, is calculated from the vertical and horizontal normal stresses ( and ) by assuming that the horizontal component is the same in the out-of-plane direction ( ), i.e. assuming that .
- ↑ Dr. Tieszen (srtiesz@sandia.gov) or Dr. O‘Hern (tjohern@sandia.gov)
Contributed by: Simon Gant — UK Health & Safety Laboratory
© copyright ERCOFTAC 2010