Hypersonic Research Facility

heater%20facilityIMG00043.jpgThis novel facility incorporates a first, electrical (hence non-vitiated), heating stage to 1200K and a second stage based on hydrogen combustion to 1850K.  Hence, flight enthalpies to Mach 6 can be simulated.  Based on the existing air supply it can operate with 3.5 lb/s continuously.  Designed by experts from CIAM, Moscow, Russia, the electric heater has no pressure vessel, hence is capable of abrupt temperature changes with rates up to 5 K/s, thus enabling transients.

More information, including examples of possible test section sizes for both internal and external flow simulation, is given here.




Supersonic combustion tunnel – vitiated

The vitiated Mach 4.7 enthalpy tunnel complements the new hypersonic facility (described separately).  It has been used for supersonic combustion of hydrogen and/or liquid and gaseous hydrocarbon fuels at isolator Mach numbers ranging from 1.3 to 3.6. The 1 x 1 in. (2.5x2.5 cm) cross section test-section is instrumented with pressure ports and thermocouples and has ample optical access via quartz windows for visualization and laser-based diagnostics. Different injection schemes have been used for studies of flameholding or injection/mixing analyses.  For liquid fuels, a separate heater is available to raise the fuel temperature up to 550K.   Compressors output continuously up to 3.5 lb/s (1.6 kg/s) with stagnation pressures up to 200 psia (1.4 MPa).




High-pressure combustion chamber

This 1” x1” (2.5x2.5 cm) cross section test chamber has been used for studies of conjugate species concentration/wall heat transfer for mixtures of hydrogen-oxygen and hydrogen-air combustion at elevated pressures up to 900 psi (6 MPa).  A coaxial injector of 75% the size of the main shuttle engine has been used to date.  A study of OH PLIF measurements uncertainty evaluated 18 parameter concluding that the largest sources of error derive from uncertain local temperature (up to 15%) and laser shot-to-shot (up to 11%). 




High-Pressure Chamber for Supercritical Studies

This facility is used for studies of subcritical-to-supercritical jet disintegration and mixing.  It is 9 inch (230 mm) long and has a 1.8” x 1.8” (46x46 mm) inner cross-section. Optical access is provided through four symmetrically located, 3.3” x 0.9” (84x22 mm) fused silica windows. The chamber can be pressurized up to 1030 psi (7 MPa) at 620K.  The injected liquid is pre-heated independently up to 675 K.  Using a fluoroketone, current studies focus on subcritical to supercritical jet disintegration in single and dual species compounds, with chamber environment from subcritical to supercritical.  These conditions appear in a broad range of applications ranging from rocket to diesel to scramjet engines.




Catalytic combustor

This facility consists of two concentric tubes where the outer surface of the inner tube is covered with a catalyst. The inner tube contains a cooling air flow while the annular region contains a fuel-air mixture that reacts on the catalytic surface. The inner and outer air flows can be independently controlled by a number of massflow controllers from Alicat, allowing equivalence ratios and fuel composition to be varied over a wide range. The incoming air streams can also be preheated through passing through two independently controlled electric heaters, allowing the conditions in a RQL low-NOx gas turbine pre-combustor to be modeled. Measurements are carried out using mass spectrometry of gas samples drawn from above the catalyst surface and through laser-based diagnostics through the fused-silica windows of the test section.




Cavitation tunnel

cavitationfacilityThe cavitation tunnel is filled with a volatile fluoroketone for studying cavitation under near-critical conditions.  This fluoroketone, like cryogenics, belongs to a class of fluids with thermosensitive properties; hence, the fluoroketone – unlike water which is more commonly used - simulates cavitation modes of cryogenic fluids.  The tunnel is capable of reaching a speed of 33 fps (10 m/s) in its 4” x4” (0.1x0.1 m) cross section test section, enabling high-Re tests under different angles of attack.  Currently a NACA 0015 hydrofoil is the test object. The tunnel is driven by a variable-speed 25 hp pump and is fitted with large windows facilitating the application of optical diagnostics, primarily PLIF. With a dedicated pulsed Nd:YAG laser and a rotating-mirror image acquisition system, frame rates of 100- 10,000 Hz are possible. The tunnel is constructed of aluminum and may be vacuumed or pressurized up to 75 psia (5 bar).  It is equipped with a 7.5kW heater and a chilled water system facilitating the investigation of both pressure and temperature effects.  Furthermore, by lowering the fluoroketone temperature cavitation modes met in water – the material used in most studies elsewhere – can be modeled. 




Mach 4 wind tunnel

The MAE department Mach 1.5-4 wind tunnel has a 6” x 6” inch (15 x15 cm) test section equipped with a sting with variable angle-of-attack as well as a Schlieren setup, a PSI9010 pressure scanner and additional pressure transducers.  The wind tunnel has access ports for secondary air injection or bleed.  Using the air storage tanks and high-pressure single-stage screw compressors, 30 s runs can be carried out approximately every 5 minutes at Mach 3.8.  This facility was used most recently used for tests of fuel injection in supersonic inlets and inlet instabilities for pulse detonation engines.




Mach 5 shock tube

The 4 inch (10 cm) diameter, double-diaphragm, shock tube generates shocks of up to Mach 5 strength. Two test sections are available at the end of the 6 m driven section. The combustion test section, separated by a thin mylar diaphragm from the driven section, is used to measure ignition delay times of premixed gases in the range of 800-2400 K using the reflected shock. CH and OH emissions can be detected by a Hamamatsu R374 photomultiplier using the appropriate narrowband filters. The second test section has a square cross section with optical access and is used for studying shock-droplet interactions and ignition using high-speed cameras.





Back to the Combustion Lab homepage.