Large Eddy Simulations of Jet Flow Interaction Within Staggered Rod Bundles

2010 ◽  
Author(s):  
Nathaniel Salpeter ◽  
Yassin Hassan
Keyword(s):  
Wavelet Transforms ◽  
Gas Flow ◽  
Jet Flow ◽  
Sensitivity Study ◽  
Impinging Jets ◽  
Large Eddy Simulations ◽  
Rod Bundle ◽  
Flow Mixing ◽  
Large Eddy ◽  
Turbulent Jet Flow

The present work investigates the turbulent jet flow mixing of downward impinging jets within a staggered rod bundle based on previous experimental work. Two inlet jets had Reynold’s numbers of 11,160 and 6,250 and were chosen to coincide with available data [Amini and Hassan 2009]. Steady state simulations were initially carried out on a semi-structured polyhedral mesh of roughly 13.2 million cells following a sensitivity study over six different discretized meshes. Very large eddy simulations were carried out over the most refined mesh and continuous 1D wavelet transforms were used to analyze the dominant instabilities and how they propagate through the system in an effort to provide some insight into potential problems relating to structural vibrations due to turbulent instabilities. The presence of strong standing horseshoe vorticies near the base of each cylinder adjacent to an inlet jet was noted and is of potential importance in the abrasion wear of the graphite support columns of the VHTR if sufficient wear particles are present in the gas flow.

Large Eddy Simulations of Jet Flow Interaction Within Staggered Rod Bundles

2010 ◽  
Author(s):  
Nathaniel Salpeter ◽  
Yassin Hassan
Keyword(s):  
Wavelet Transforms ◽  
Gas Flow ◽  
Jet Flow ◽  
Sensitivity Study ◽  
Impinging Jets ◽  
Large Eddy Simulations ◽  
Rod Bundle ◽  
Flow Mixing ◽  
Large Eddy ◽  
Turbulent Jet Flow

The present work investigates the turbulent jet flow mixing of downward impinging jets within a staggered rod bundle based on previous experimental work. The two inlet jets had Reynold’s numbers of 11,160 and 6,250 and were chosen to coincide with available data [Amini and Hassan 2009]. Steady state simulations were initially carried out on a semi-structured polyhedral mesh of roughly 13.2 million cells following a sensitivity study over six different discretized meshes. Very large eddy simulations were carried out over the most refined mesh and continuous 1D wavelet transforms were used to analyze the dominant instabilities and how they propagate through the system in an effort to provide some insight into potential problems relating to structural vibrations due to turbulent instabilities. The presence of strong standing horseshoe vorticies near the base of each cylinder adjacent to an inlet jet was noted and is of potential importance in the abrasion wear of the graphite support columns of the VHTR if sufficient wear particles are present in the gas flow.

Large eddy simulations of the all-speed turbulent jet flow using 3-D CFD code GASFLOW-MPI

2018 ◽  
Vol 328 ◽  
pp. 134-144 ◽  
Author(s):  
Han Zhang ◽  
Yabing Li ◽  
Jianjun Xiao ◽  
Thomas Jordan
Keyword(s):  
Jet Flow ◽  
Large Eddy Simulations ◽  
Turbulent Jet ◽  
Large Eddy ◽  
Turbulent Jet Flow

Large Eddy Simulations of Supersonic Impinging Jets

2012 ◽  
Vol 134 (12) ◽  
Author(s):  
James P. Erwin ◽  
Neeraj Sinha ◽  
Gregory P. Rodebaugh
Keyword(s):  
Impinging Jet ◽  
Jet Flow ◽  
The United States ◽  
Flow Fields ◽  
Impinging Jets ◽  
Far Field ◽  
Nozzle Throat ◽  
Aircraft Carrier ◽  
Large Eddy ◽  
Short Takeoff And Landing

Supersonic impinging jet flow fields contain self-sustaining acoustic feedback features that create high levels of tonal noise. These types of flow fields are typically found with short takeoff and landing military aircraft as well as jet blast deflector operations on aircraft carrier decks. The United States Navy has a goal to reduce the noise generated by these impinging jet configurations and is investing in computational aeroacoustics to aid in the development of noise reduction concepts. In this paper, implicit large eddy simulation (LES) of impinging jet flow fields are coupled with a far-field acoustic transformation using the Ffowcs Williams and Hawkings (FW-H) equation method. The LES solves the noise generating regions of the flow and the FW-H transformation is used to predict the far-field noise. The noise prediction methodology is applied to a Mach 1.5 vertically impinging jet at a stand-off distance of five nozzle throat diameters. Both the LES and FW-H acoustic predictions compare favorably with experimental measurements. Time averaged and instantaneous flow fields are shown. A calculation performed previously at a stand-off distance of four nozzle throat diameters is revisited with adjustments to the methodology including a new grid, time integrator, and longer simulation runtime. The calculation exhibited various feedback loops which were not present before and can be attributed to an explicit time marching scheme. In addition, an instability analysis of the heated jets at both stand-off distances is performed. Tonal frequencies and instability modes are identified for the sample problems.

Large-eddy simulations of plane impinging jets

1995 ◽  
Vol 38 (3) ◽  
pp. 489-507 ◽  
Author(s):  
Peter R. Voke ◽  
Shian Gao ◽  
David Leslie
Keyword(s):  
Impinging Jets ◽  
Large Eddy Simulations ◽  
Large Eddy
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