Abstract
Numerical simulations of a scramjet combustor were conducted to determine the effects of design changes on mixing and combustion characteristics and to investigate the physics of the supersonic combustion flowfield. The mixing and combustion performances might be greatly affected by numerical diffusion due to a low grid density in the computational domains. Two test cases were examined to check the effects of numerical diffusion on the flowfields relating to the scramjet combustor. One was a complex shape closely approximating a scramjet and the other was simple transverse injection through a circular hole in a flat plate. In the two cases, the contamination levels of the flowfields by the numerical diffusion were very different. In the scramjet simulations, comparisons between the physical diffusion and the numerical diffusion indicated that the effects of the numerical diffusion are acceptable for finer solutions. In fact, the combustion efficiency converged within ±5 % at the grid with 2-mm spacing. On the other hand, the numerical diffusion of the flat plate injection using a 0.5-mm grid was comparable to the physical diffusion. The grid convergence was not proved in the current grid systems. These differences were caused by the high eddy viscosity due to the shock train of the scramjet combustor.
| Original language | English |
|---|---|
| Title of host publication | A Collection of Technical Papers - 13th AIAA/CIRA International Space Planes and Hypersonic Systems and Technologies Conference |
| Pages | 111-121 |
| Number of pages | 11 |
| Volume | 1 |
| Publication status | Published - 2005 |
| Externally published | Yes |
| Event | 13th AIAA/CIRA International Space Planes and Hypersonic Systems and Technologies Conference - Capua, Italy Duration: May 16 2005 → May 20 2005 |
Other
| Other | 13th AIAA/CIRA International Space Planes and Hypersonic Systems and Technologies Conference |
|---|---|
| Country | Italy |
| City | Capua |
| Period | 5/16/05 → 5/20/05 |
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ASJC Scopus subject areas
- Engineering(all)
Cite this
Problems of numerical diffusion found in scramjets. / Kouchi, Toshinori; Mitani, Tohru; Masuya, Goro.
A Collection of Technical Papers - 13th AIAA/CIRA International Space Planes and Hypersonic Systems and Technologies Conference. Vol. 1 2005. p. 111-121.Research output: Chapter in Book/Report/Conference proceeding › Conference contribution
}
TY - GEN
T1 - Problems of numerical diffusion found in scramjets
AU - Kouchi, Toshinori
AU - Mitani, Tohru
AU - Masuya, Goro
PY - 2005
Y1 - 2005
N2 - Numerical simulations of a scramjet combustor were conducted to determine the effects of design changes on mixing and combustion characteristics and to investigate the physics of the supersonic combustion flowfield. The mixing and combustion performances might be greatly affected by numerical diffusion due to a low grid density in the computational domains. Two test cases were examined to check the effects of numerical diffusion on the flowfields relating to the scramjet combustor. One was a complex shape closely approximating a scramjet and the other was simple transverse injection through a circular hole in a flat plate. In the two cases, the contamination levels of the flowfields by the numerical diffusion were very different. In the scramjet simulations, comparisons between the physical diffusion and the numerical diffusion indicated that the effects of the numerical diffusion are acceptable for finer solutions. In fact, the combustion efficiency converged within ±5 % at the grid with 2-mm spacing. On the other hand, the numerical diffusion of the flat plate injection using a 0.5-mm grid was comparable to the physical diffusion. The grid convergence was not proved in the current grid systems. These differences were caused by the high eddy viscosity due to the shock train of the scramjet combustor.
AB - Numerical simulations of a scramjet combustor were conducted to determine the effects of design changes on mixing and combustion characteristics and to investigate the physics of the supersonic combustion flowfield. The mixing and combustion performances might be greatly affected by numerical diffusion due to a low grid density in the computational domains. Two test cases were examined to check the effects of numerical diffusion on the flowfields relating to the scramjet combustor. One was a complex shape closely approximating a scramjet and the other was simple transverse injection through a circular hole in a flat plate. In the two cases, the contamination levels of the flowfields by the numerical diffusion were very different. In the scramjet simulations, comparisons between the physical diffusion and the numerical diffusion indicated that the effects of the numerical diffusion are acceptable for finer solutions. In fact, the combustion efficiency converged within ±5 % at the grid with 2-mm spacing. On the other hand, the numerical diffusion of the flat plate injection using a 0.5-mm grid was comparable to the physical diffusion. The grid convergence was not proved in the current grid systems. These differences were caused by the high eddy viscosity due to the shock train of the scramjet combustor.
UR - http://www.scopus.com/inward/record.url?scp=29044434566&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=29044434566&partnerID=8YFLogxK
M3 - Conference contribution
AN - SCOPUS:29044434566
SN - 1563477297
SN - 9781563477294
VL - 1
SP - 111
EP - 121
BT - A Collection of Technical Papers - 13th AIAA/CIRA International Space Planes and Hypersonic Systems and Technologies Conference
ER -