Experimental Investigation of the Very Near Pressure Field of a Heated Supersonic Jet with a Total Temperature Non-Uniformity

2018 ◽  
Author(s):  
Kyle Daniel ◽  
David E. Mayo ◽  
Todd Lowe ◽  
Wing Ng
Keyword(s):  
Experimental Investigation ◽  
Pressure Field ◽  
Supersonic Jet ◽  
Total Temperature

Crackle Noise in Heated Supersonic Jets

2013 ◽  
Vol 135 (5) ◽  
Author(s):  
Joseph W. Nichols ◽  
Sanjiva K. Lele ◽  
Frank E. Ham ◽  
Steve Martens ◽  
John T. Spyropoulos
Keyword(s):  
Large Scale ◽  
Supersonic Jet ◽  
Supersonic Jets ◽  
Scale Model ◽  
Positive Pressure ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Total Temperature ◽  
Large Scale Flow ◽  
Large Eddies

Crackle noise from heated supersonic jets is characterized by the presence of strong positive pressure impulses resulting in a strongly skewed far-field pressure signal. These strong positive pressure impulses are associated with N-shaped waveforms involving a shocklike compression and, thus, is very annoying to observers when it occurs. Unlike broadband shock-associated noise which dominates at upstream angles, crackle reaches a maximum at downstream angles associated with the peak jet noise directivity. Recent experiments (Martens et al., 2011, “The Effect of Chevrons on Crackle—Engine and Scale Model Results,” Proceedings of the ASME Turbo Expo, Paper No. GT2011-46417) have shown that the addition of chevrons to the nozzle lip can significantly reduce crackle, especially in full-scale high-power tests. Because of these observations, it was conjectured that crackle is associated with coherent large scale flow structures produced by the baseline nozzle and that the formation of these structures are interrupted by the presence of the chevrons, which leads to noise reduction. In particular, shocklets attached to large eddies are postulated as a possible aerodynamic mechanism for the formation of crackle. In this paper, we test this hypothesis through a high-fidelity large-eddy simulation (LES) of a hot supersonic jet of Mach number 1.56 and a total temperature ratio of 3.65. We use the LES solver CHARLES developed by Cascade Technologies, Inc., to capture the turbulent jet plume on fully-unstructured meshes.

Experimental Investigation of Nozzle Exit Reflector Effect on Supersonic Jet

Shock Waves ◽  
2006 ◽  
Vol 15 (3-4) ◽  
pp. 229-239 ◽  
Author(s):  
Y.-H. Kweon ◽  
Y. Miyazato ◽  
T. Aoki ◽  
H.-D. Kim ◽  
T. Setoguchi
Keyword(s):  
Experimental Investigation ◽  
Nozzle Exit ◽  
Supersonic Jet

An Experimental Investigation on Transpiration Cooling for Supersonic Vehicle Nose Cone Using Porous Material

2014 ◽  
Vol 541-542 ◽  
pp. 690-694 ◽  
Author(s):  
Lian Jin Zhao ◽  
Jia Lin ◽  
Jian Hua Wang ◽  
Jin Long Peng ◽  
De Jun Qu ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
Porous Material ◽  
Supersonic Jet ◽  
Leading Edge ◽  
Injection System ◽  
Aerodynamic Heating ◽  
Hypersonic Vehicles ◽  
Transpiration Cooling ◽  
Cone Model ◽  
Nose Cone

During hypersonic flight or cruise in the near space, the aerodynamic heating causes a very high temperature on the leading edge of hypersonic vehicles. Transpiration cooling has been recognized the most effective cooling technology. This paper presents an experimental investigation on transpiration cooling using liquid water as coolant for a nose cone model of hypersonic vehicles. The nose cone model consists of sintered porous material. The experiments were carried out in the Supersonic Jet Arc-heated Facility (SJAF) of China Academy of Aerospace Aerodynamics (CAAA) in Beijing. The cooling effect in the different regions of the model was analyzed, and the shock wave was exhibited. The pressure variations of the coolant injection system were continuously recorded. The aim of this work is to provide a relatively useful reference for the designers of coolant driving system in practical hypersonic vehicles.

Experimental Investigation of Flow Induced Rotor Oscillations in a Centrifugal Sewage Water Pump

Volume 3 ◽  
2004 ◽  
Author(s):  
Friedrich-Karl Benra ◽  
Hans Josef Dohmen ◽  
Oliver Schneider
Keyword(s):  
Experimental Investigation ◽  
Static Pressure ◽  
Pressure Field ◽  
Pressure Fluctuations ◽  
Sewage Water ◽  
Water Pump ◽  
Flow Rates ◽  
Pump Rotor ◽  
Pump Shaft ◽  
Impeller Geometry

Most of the pumps for sewage transport have a special impeller geometry in order to avoid operational disturbances by clogging. The almost exclusively used single stage machines particularly are equipped with single-blade impellers. With this impeller geometry a strongly uneven pressure field along the perimeter of the pump casing can be expected. The resulting periodically unsteady flow forces affect the impeller and produce strong radial deflections of the pump shaft. In this contribution the experimental investigation of the dynamic behavior of the pump rotor as a consequence of the transient hydrodynamic forces is described. To verify the calculated rotor oscillations measurements were performed at several rotating speeds and at different volume flow rates. The pump which before has been investigated numerical was equipped with several sensors. The deflections of the pump rotor were measured with two proximity sensors. The measurement of the vibration accelerations at the pump casing showed the effects of the transient hydrodynamic stimulation forces. Measurements of the static pressure in the casing allowed a correlation between the rotor oscillations and the pressure fluctuations produced by the single-blade impeller.

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