The Skytop Tunnel is a Mach 1.6 capable facility located at 621 Skytop Rd on South Campus at Syracuse University. The facility features a 2 stage 100 HP Joy Compressor with 45 cubic meters of compressor storage at up to 500 PSI (3.4 MPa). The blow down is controlled by a pneumatically actuated Fisher butterfly valve which is operated by a 100 psi Kaiser compressor. The Anechoic Chamber is acoustically treated with fiberglass wedges featuring a ~150 Hz cut-off frequency in a ~200 cubic meter room. The roof of the facility features an Industrial Commercial Equipment HVAC system which allows for temperature control. This also doubles providing a co-flow around the jet which allows for seeding of the ambient fluid during PIV experiments. The chamber itself contains the SERN, PIV system, near-field pressure array, and an acoustic microphone array. The near-field pressure array features 6 Kulite dynamic pressure transducers operating at a 50kHz bandwidth. The acoustics array contains 9 GRAS 46 BE Microphones operating at 100kHz with a 0-160 dB range spread 15 degrees apart in the same plane as the nozzle. The facility also contains a 900 kW Chromalox heater used to heat the jet when necessary up to 1000 degrees F. The figure to the right shows the floorplan of the anechoic chamber with the following: A.Plenum Chamber; B. Jet Feed Pipe (to compressed air tanks); C. Bypass Air Flow Straightener; D. Jet Rig; E. Anechoic Chamber; F. Plume Catcher; G. Far-Field Condenser Microphones; H. Fiberglass Wedges; I. Exhaust Path;
Our Multi Aperature Rectangular Single Expansion Ramp Nozzle (MARS) features canonical flows that mix aft of a splitter plate. These flows exhaust onto an aft deck plate to represent the surface/airframe of an aircraft. Experiments are typically run with a Nominal Pressure Ratio (NPR) of 4.25 for the core flow (combination of the typcial hot core and bypass streams in a turbofan engine) and 1.89 for the third stream (an additional cold stream injected which carries a variety of benefits). These NPRs correspond to Mach numbers of 1.6 and 1.0 respectively. The nozzle exit features a width of 82.3 mm and a height of 30 mm. Currently, research is aimed at exploring various aspects of the complex region aft of the splitter plate, while simultaneously applying modern computational methods to optimize the geometry of the splitter plate and aft-deck plate.
A standard Dantec Dynamics PIV system is utilized to capture velocity field measurements. Stereo PIV is utilized with camera offsets and three-dimensional calibration. The core flow is seeded with a ViCount 1300 smoke generator with aerosolized white mineral oil which is then exhausted before condensing into droplets about 600 nm in diameter. The co-flow is seeded using two Ultratec show foggers to form theatrical smoke with particle diameters of ~2 micrometers. Two FlowSense EO 4MP cameras are utilized to capture stereo velocity measurements in the streamwise plane. A New Wave Gemini Nd:YAG laser is used as the light source in conjunction with a Dantec Dynamics sheet optics system before being reflected upwards. Timing is synchronized to within 1 nanosecond by a NI PCIe-6612 acquisition card. PIV images were captured at 10 Hz with over 800 image pairs acquired from each camera per run.
The Indoor Flow Lab (IFL) is a 15x18x10 foot closed room within the Skytop Facility capable of performing indoor UAS experiments. It features ample space to fit multiple unmanned systems in close proximity. Specifically, the room allows for ambient seeding for flow visualization of UAS, hotwire anemometry, and holds a Scanivalve PDM 1500 pressure rake system. A Dantec Dynamics PIV system is also installed in the IFL. Currently, multiple DJI Phantom 3 drones are installed with the goal of characterizing the turbulent wake of quadrotor swarms. More information can be found on the Unmanned Systems page.
The exterior shear flow generator was constructed in 2019 for use with UAS projects. It features both an open and honeycomb structure connected to the exhaust system of the anechoic chamber. This variable-speed exhaust system features a Harztell 54 inch Belt Drive Vaneaxial Fan controlled by a Yaskawa Z1000 Series Frequency Drive. A UAS mount and gimbal system is located 10 feet downstream of the shear flow generator to mount UAS systems within the shear flow for analyses. The facility also features a protective tent to prevent additional flows and weather from compromising experiments.
The sub-sonic wind tunnel is located in Link Hall on the main campus of Syracuse University. It is a closed-loop facility with a 2x2 foot test section spanning 7 feet long. It features a six-degree-of-freedom variable sting mount capable of recording forces experienced by an object within the test section. It also contains multiple pressure tap systems to record velocities of the flow along with specific boundary layer measurements.