Gas Turbine Laboratory

Students in the Gas Turbine Laboratory at ERAU work with leading aerospace corporations and privately owned companies and assist with Intellectual Property development.

The faculty and student researchers in this space have an academic and commercial focus on advancing innovative topics in the aeropropulsion community. Current studies at the Gas Turbine Laboratory target the following distinct areas of numerical and experimental research:

• Deflagration to detonation transition in turbulent flow
• Effects of pulse detonation on axial turbine performance
• Development of a Hybrid Vortex theory for turbomachinery blade design
• Efficiency optimization for ultra-high pressure ratio centrifugal compressors
• Horseshoe vortex mitigation in axial turbine vanes through velocity triangle optimization
• Active stall recovery of compressor systems through counter-rotation

Equipment

• Shock tubes
• High-response pressure transducers (PCB)
• Temperature and pressure sensitive paint system
• Pitot tubes
• Thermocouple arrays
• Various data collection equipment such as DAQ boards and oscilloscopes
• Several engines including: GE TF-34, Garrett TPF 351-20, P&W JT8-15D, and GE CF6-6
• Temperature/Pressure Sensitive Paint System
• Acrylic Internal Channels: Pin Fin, Impingement, Ribbed, Smooth
• External Impingement Nozzle (Variable angle & height. Local & average data
• High performance Dell workstations 
• COE VEGA Cluster access 
• Experience/Access to various commercial software: Star-CCM+, Optimate+, COMSOL, MATLAB, etc.  

Active Research Topics

Pulse Detonation Engine Studies

Graduate students have been advancing pulse detonation (PDE) theory at the ERAU GTL through numerical and experimental trials. Detonation is a pressure-gain combustion process which can increase thermal efficiency by anywhere from 10-50%; the process promises significantly lower emissions as well. Previously at the GTL, transient studies of deflagration to detonation transition (DDT) in turbulent flow by means of geometry optimization of flow obstacles were studied through the use of Computational Fluid Dynamics. Concurrently, a pulse detonation engine testbed was built for experimental studies of DDT. After successful trials, focus has been directed towards the application of PDE technology in gas turbine engine application. Students are currently actively engaged in deriving necessary analytical flow models that could later be used for the design optimization of axial flow turbines to be integrated with these Pressure Gain Combustion (PGC) devices, while simultaneously exploring sensitivity analyses varying the blockage section of the PDE testbed for DDT optimization; the results of this study will directly lead to the derivation of empirical relations that will shorten the time necessary for deflagration to transition into detonation.

Hybrid Vortex Theory

Turbo machinery blade design is challenged by the reality of three-dimensional flow effects (i.e. presence of endwall viscous layers, inlet flow non-uniformity, etc.), requiring the utilization of 3D design solutions to adequately establish blade geometry from hub to shroud. These 3D design solutions are met with distinct challenges due to the nonlinearity of the equations of motion governing the turbulent flow through turbomachinery, requiring simplifying assumptions for the physical modeling. Graduate students are developing an innovative methodology that will allow for turbomachinery designers to more accurately develop particular blade geometry.

Centrifugal Compressor Optimization

Graduate students are interested in optimizing the efficiency for Ultra High Pressure Ratio centrifugal compressors.

Horseshoe Vortex Mitigation

Momentum differences between the neighboring streamlines at the end wall/primary flow interaction region of an axial turbine stage induce three-dimensional vortical flow structures, such as the leading edge horseshoe vortex, resulting in significant aerodynamic performance deterioration. Reducing the effect of such flow instabilities requires turbine blade modification to discourage boundary layer roll-up, and graduate students are leading this effort through a blade modification method involving velocity triangle-driven optimization designed to adjust the leading edge airfoil shape in horseshoe vortex-affected turbine applications.

Compressor Active Stall Recovery

There are various types of aerodynamic and mechanical instabilities that arise in an axial compressor systems, however stall and surge are the most common and can be catastrophic for gas turbine engines. Various methods have been devised to control and eliminate stall in an axial compressor, and can be distinctively divided into two parts: active stall control and passive stall control, with active stall control leading the focus of this study. In an active system, compressor stall is avoided or eliminated by dynamically changing compressor characteristics. Graduate students are evolving compressor active control theory through innovative use of counter-rotation; stall recovery is achieved by RPM variation. Computational Fluid Dynamics are aiding in the efforts of simulating a 2-stage counter-rotating compressor design.