<p>Within the gas turbine industry,
turbofan engines are widely implemented to enhance engine efficiency, specific
thrust, and specific fuel consumption. However, these turbofans have yet to be
widely implemented into microgas turbine engines. As turbofans become
implemented into smaller engines, the need to design engine intakes for
high-speed mission becomes more vital. In this work, a design procedure for
compact, highly diffusive engine intakes for high subsonic speed applications
is set about. The aerodynamic tradeoffs between cruise and takeoff flights are
discussed and methods to enhance takeoff performance without negatively
impacting high-speed cruise performance is discussed. Intake performance is
integrated into overall engine analysis to help guide future mission analyses.
Finally, an experimental model for engine intakes is developed for application
to linear wind tunnels; allowing future designers to effectively validate
numerical results.<br></p>
<p>A multi-objective optimization routine is performed for
compact engine intakes at a Mach number of 0.9. This optimization routine
yielded a family of related curves that maximize intake diffusive capability
and minimize intake pressure losses. Design recommendations to create such
optimal intakes are discussed in this work so that future designers do not need
to perform an optimization. Due to high diffusion rate of the intake, the
intake performance at takeoff suffers greatly (as measured by massflow
ingestion). Methods to enhance takeoff performance, from designing a variable
geometry intake, to creating slots, to sliding intake components are evaluated
and ranked for future designers to get an order of magnitude understanding of
the types of massflow enhancements possible. Then, off-design performance of
the intake is considered: with different Mach number flights, non-axial flow
conditions, various altitudes, and unsteady engine operation considered. These
off-design effects are evaluated to generate an intake map across a wide engine
operational envelope. This map is then inputted into an engine model to
generate a performance map of an engine; which allows for mission planning
analysis. Finally, various methods to replicate intake flow physics in a linear
wind tunnel are considered. It is shown that replicating diffuser curvature in
a linear wind tunnel allows for best replication of flow physics. Additionally,
a method to non-dimesnsionalize intake performance for application to a wind
tunnel is developed. </p>
<p>This work can be utilized by future engine intake
designers in a variety of ways. The results shown here can help guide future
designers create highly compact diffuser technology, capable of operating
across a wide breadth of conditions. Methods to assess intake performance effects
on overall engine performance are demonstrated; and an experimental approach to
intake analysis is developed.</p>
| Identifer | oai:union.ndltd.org:purdue.edu/oai:figshare.com:article/8044529 |
| Date | 10 June 2019 |
| Creators | Udit Vyas (6636125) |
| Source Sets | Purdue University |
| Detected Language | English |
| Type | Text, Thesis |
| Rights | CC BY 4.0 |
| Relation | https://figshare.com/articles/Aerodynamic_Optimization_of_Compact_Engine_Intakes_for_High_Subsonic_Speed_Turbofans/8044529 |
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