Numerical Investigation of Diffusers in Arc-Heated Wind Tunnel: Introducing a Novel and Efficient Hypersonic Diffuser
Publication: Journal of Aerospace Engineering
Volume 35, Issue 5
Abstract
To develop an efficient hypersonic diffuser, a numerical investigation was performed on a center-body diffuser and a second-throat cylindrical diffuser of a large-scale arc-heated wind tunnel with a Mach number 6 nozzle. The length of the diffuser was set to 16 m, and the total pressure and temperature were over 28 atm (2,837 kPa) and 2,000 K to simulate a 13-MW wind tunnel. The ARCFLO4 code was used for the investigation and flow analysis, with air as the working gas inside the wind tunnel, assumed to be in thermal and chemical equilibrium. The axisymmetric Reynolds-averaged Navier-Stokes equation was used as the governing equation. The flow structure and characteristics inside each diffuser were analyzed and compared, and a novel diffuser shape locating a center body in the subsonic region was proposed to compensate for the disadvantages of each diffuser. Moreover, the performance of each diffuser was evaluated based on the maximum efficiency, cooling effect, and exit velocity. The proposed diffuser showed the lowest exit temperature, enthalpy, and velocity with high efficiency; therefore, the proposed diffuser is expected to reduce the cost of wind tunnel installation and operation, alleviating the requirements of the heat exchanger or vacuum chamber.
Practical Applications
By performing a numerical investigation on general diffuser types of a high-enthalpy wind tunnel, a novel diffuser is introduced here that can lower the exit velocity, temperature, and enthalpy of the internal flow. The proposed diffuser has a center body with a cooling system in the subsonic flow region to minimize the total pressure loss and reduce flow velocity and temperature. In particular, it is effective in reducing the elevated flow temperature due to the shock wave of the supersonic flow. This study is applicable to not only the diffuser but also pipe flow; kinetic energy loss may occur due to the center body by reducing effective area, but the efficiency of the device is almost maintained, but the temperature and enthalpy of the flow are reduced. By adding a center body, it is possible to design and manufacture an efficient new device; further, it may have the advantages of extending the operating range to an existing device by adding a center body.
Get full access to this article
View all available purchase options and get full access to this article.
Data Availability Statement
Some or all data, models, or code that support the findings of this study are available from the corresponding author upon reasonable request:
1.
validation and verification data and results, and
2.
numerical results.
Acknowledgments
The authors gratefully acknowledge the financial support provided by Defense Acquisition Program Administration and Agency for Defense Development under Contract UG200064GD.
References
Agostinelli, P., E. Trifoni, and R. Savino. 2019. “Aerothermodynamic analysis and redesign of Ghibli plasma wind tunnel hypersonic diffuser.” Aerosp. Sci. Technol. 87 (Feb): 218–229. https://doi.org/10.1016/j.ast.2019.02.023.
Anderson, J. D. 2006. Hypersonic and high-temperature gas dynamics. Reston, VA: American Institute of Aeronautics and Astronautics.
Buscher, M., B. Esser, K. Kindler, and V. List. 1995. “Developments at the arc heated facility LBK of DLR.” In Vol. 367 of Aerothermodynamics for space vehicles, 357. Paris: European Space Agency.
Choi, D., J. S. Baek, and K.-H. Kim. 2021. “Efficient diffuser design for plasma wind tunnels with a large blockage model.” Aerosp. Sci. Technol. 119 (2): 107206. https://doi.org/10.1016/j.ast.2021.107206.
Fouladi, N., and M. Farahani. 2020. “Numerical investigation of second throat exhaust diffuser performance with thrust optimized parabolic nozzles.” Aerosp. Sci. Technol. 105 (Oct): 106020. https://doi.org/10.1016/j.ast.2020.106020.
Gupta, R., K.-P. Lee, R. Thompson, and J. M. Yos. 1991. Calculations and curve fits of thermodynamic and transport properties for equilibrium air to 30000 k. Rep. No. Nas 1.61:1260, NASA-RP-1260. Washington, DC: National Aeronautics and Space Administration (NASA).
Guy, R., R. Rogers, R. Puster, K. Rock, and G. Diskin. 1996. “The NASA Langley scramjet test complex.” In Proc., 32nd Joint Propulsion Conf. and Exhibit. Reston, VA: American Institute of Aeronautics and Astronautics. https://doi.org/10.2514/6.1996-3243.
Hermann, R. 1950. Diffuser efficiency and flow process of supersonic wind tunnels with free jet test section. AF Technical Rep. No.6334. Dyton, Ohio: US Air Force Air Materiel Command Wright-Patterson Air Force Base.
Jones, W., and B. Launder. 1972. “The prediction of laminarization with a two-equation model of turbulence.” Int. J. Heat Mass Transfer 15 (2): 301–314. https://doi.org/10.1016/0017-9310(72)90076-2.
Kim, K. 2011. “Numerical investigation of plasma flows inside segmented constrictor type arc-heater.” In Tech: Aeronautics and astronautics, 97–124. Croatia: InTech. https://doi.org/10.5772/18769.
Kim, K. H., C. Kim, and O.-H. Rho. 2001. “Methods for the accurate computations of hypersonic flows: I. AUSMPW+ scheme.” J. Comput. Phys. 174 (1): 38–80. https://doi.org/10.1006/jcph.2001.6873.
Lee, J.-I., C. Kim, and K.-H. Kim. 2007. “Accurate computations of arc-heater flows using two-equation turbulence models.” J. Thermophys. Heat Transfer 21 (1): 67–76. https://doi.org/10.2514/1.25495.
Menter, F. R. 1994. “Two-equation eddy-viscosity turbulence models for engineering applications.” AIAA J. 32 (8): 1598–1605. https://doi.org/10.2514/3.12149.
Milligan, M., and J. Bailey. 1963. Low-density hypervelocity wind tunnel diffuser performances. Washington, DC: NASA.
Monti, R., D. Paterna, R. Savino, and A. Esposito. 2001. “Low-reynolds number supersonic diffuser for a plasma-heated wind tunnel.” Int. J. Therm. Sci. 40 (Jan): 804–815. https://doi.org/10.1016/S1290-0729(01)01267-4.
Pugazenthi, R. S., and A. C. McIntosh. 2011. “Design and performance analysis of a supersonic diffuser for plasma wind tunnel.” Int. J. Mech. Indus. Aerosp. Sci. 5 (8): 1682–1687. https://doi.org/10.5281/zenodo.1330939.
Savino, R., R. Monti, and A. Esposito. 1999. “Behaviour of hypersonic wind tunnels diffusers at low reynolds numbers.” Aerosp. Sci. Technol. 3 (99): 11–19. https://doi.org/10.1016/S1270-9638(99)80018-2.
Srinivasan, S., J. Tannehill, and K. Weilmuenster. 1987. Simplified curve fits for the thermodynamic properties of equilibrium air. Rep. No. Nas 1.61:1181, NASA-RP-1181. Washington, DC: NASA.
Takahashi, Y., H. Kihara, and K.-I. Abe. 2010. “Numerical investigation of nonequilibrium plasma flows in constrictor- and segmented-type arc heaters.” J. Thermophys. Heat Transfer 24 (1): 31–39. https://doi.org/10.2514/1.43565.
Thomas, S., and R. W. Guy. 1983. Expanded operational capabilities of the langley Mach 7 scramjet test facility. Rep. No. Nas 1.60:2186, NASA-TP-2186. Washington, DC: NASA.
Wilcox, D. C. 1998. Turbulence modeling for CFD. Flintridge, CA: DCW Industries, Inc.
Yoon, S., and A. Jameson. 1988. “Lower-upper symmetric-gauss-seidel method for the euler and navier-stokes equations.” AIAA J. 26 (9): 1025–1026. https://doi.org/10.2514/3.10007.
Information & Authors
Information
Published In
Journal of Aerospace Engineering
Volume 35 • Issue 5 • September 2022
Copyright
© 2022 American Society of Civil Engineers.
History
Received: Jan 7, 2022
Accepted: May 6, 2022
Published online: Jun 30, 2022
Published in print: Sep 1, 2022
Discussion open until: Nov 30, 2022
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.