Critical flow of nitrogen and water through a nozzle
Abstract
Critical flow of nitrogen-water mixtures through a nozzle positioned in a vertical pipe with upward flow was studied. The flow rates of nitrogen and water from 7370 cu m/s to 10840 cu m/s at STP (15.6 to 22.2 scfm) and 355 cu m/s to 505 cu m/s (5.63 to 8.01 gpm), respectively. A 0.49 cm (0.93 in.) exit diameter, stainless steel nozzle was fitted inside a stainless steel pipe 1.516 cm (0.597 in.) in ID. The upstream critical pressure increased with increasing flow rates of nitrogen and water. An iterative empirical correlation was developed to predict upstream and vena contracta critical pressures for given nitrogen and water flow rates, temperature, and nozzle area. Upper and lower bounds for the upstream critical pressure were predicted theoretically. The upper bound, derived assuming homogeneous equilibrium flow, overpredicted the experimental value at each run by 0.31 +- 0.04 MPa (45 +- 5.8 psia)
- Publication:
-
NASA STI/Recon Technical Report N
- Pub Date:
- October 1982
- Bibcode:
- 1982STIN...8321296S
- Keywords:
-
- Critical Flow;
- Nitrogen;
- Nozzle Flow;
- Pipe Flow;
- Upstream;
- Water Flow;
- Coal Liquefaction;
- Critical Pressure;
- Flow Velocity;
- Iterative Solution;
- Mass Flow Rate;
- Temperature Gradients;
- Fluid Mechanics and Heat Transfer