Research was performed to optimize the high-efficiency jet ejector geometry by
varying motive velocities from Mach 0.50 to 3.25, and mass flow ratio from 0.02 to
100.0. The high-efficiency jet ejector was simulated by Fluent Computational Fluid
Dynamics (CFD) software. A conventional finite-volume scheme was utilized to solve
two-dimensional transport equations with the standard k-ε turbulence model. In the
optimization study of the constant-area jet ejectors, all parameters were expressed in
dimensionless terms. The objective of the study was to investigate the optimal length,
throat diameter, and optimal nozzle diameter at any operating conditions. Also, the
optimum compression ratio and efficiency were calculated.
By comparing simulation results to an experiment, CFD modeling has shown
high-quality results. The overall deviation was 8.19%, thus confirming the reliability of
the modeling results.
The results from the optimization study indicate that the jet ejector efficiency
improves significantly compared to a conventional jet-ejector design. In cases with a
subsonic motive velocity, the efficiency of the jet ejector is greater than 90%. A high
compression ratio can be achieved with greater motive velocity and mass flow ratio. The ejector performance between the optimal jet ejectors and conventional jet ejectors
provided by Graham Corporation was compared. The results show that substituting a
single optimal jet ejector for a single conventional ejector reduces the motive stream
consumption by about 10% to 30%, which could decrease operating costs tremendously.
Dimensionless group analysis reveals that the research results are valid for any
fluid, operating pressure and geometric scale for a given motive-stream Mach number
and momentum ratio. The explanation of how to implement the optimization results and
selecting the best operating conditions to minimize the motive stream consumption was
included at the end of the dissertation.
| Identifer | oai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/ETD-TAMU-2387 |
| Date | 2008 May 1900 |
| Creators | Watanawanavet, Somsak |
| Contributors | Holtzapple, Mark T. |
| Source Sets | Texas A and M University |
| Language | English |
| Detected Language | English |
| Type | Book, Thesis, Electronic Dissertation, text |
| Format | electronic, application/pdf, born digital |
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