Basic Two-Phase Flow
A vertical pipe 0.1
meters in diameter is instrumented with differential pressure taps at
every meter along its length. The pipe is filled with water, and
air injected as bubbles in a uniform pattern across the bottom at a
total rate of 9.55e-5 kg/s. The pressure difference between the
two taps closest to the surface of the bubbly mixture is 9.289e+3
Pa. You can assume that:
Provide the following additional information about the state of the two
phase system, showing all calculations.
- Temperature is uniform at 300K;
- Pressure at the surface of the bubbly mixture is 1.0e5
- Water is
stationary at any given location; and
- Bubbles are
moving at their terminal rise velocity.
- What is the mean void fraction in the volume bounded by the
- What is the mean bubble rise velocity in this volume?
- Find and document an expression for the drag force on a moving
sphere. Balancing that against the bouyancy force on an
individual bubble, give an estimate for the bubble diameter.
- Give an estimate of the mean center-to-center separation distance
Remember, if you use MathCad for
supporting calculations, copy the results into your report, don't give
me a .mcd file.
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