About Shock Wave and Space Propulsion Laboratory

We aim for innovations in aero/astronautics and propulsion with understanding physics of shock waves and plasma/high-enthalpy flows.

Shock wave-turbulence interactions

When a shock wave propagates through a turbulent flow, complex changes occur. This phenomenon is closely related to the noise problem caused by the shock wave generated in supersonic flight (sonic boom). In order to predict the strength of a sonic boom that changes due to atmospheric turbulence, it is necessary to understand such complex fluid physics.

In our laboratory, we have developed a “counter-driver shock tube (CD-ST)” [1] that can perform interactions between shock waves and various flows. We are conducting the experiments of the interaction of shock wave with grid turbulence. The shock wave propagating through grid turbulence was visualized changing the strength of the shock wave and the turbulence intensity. As a result, it was confirmed that the deformation of the shock wave progressed as the interaction length of the shock wave and turbulence increased. Among the experiments we have conducted, the interaction between the strongest turbulence (turbulence Mach number *1 Mt = 0.024) and shock wave (shock wave Mach number *2 Ms = 1.03) showed interesting phenomena. Although the shock wave was straight soon after the start of interaction (Interaction length: 65 mm), it became deformed and dispersed when the interaction length exceeded 1 m (Interaction length: 1121 mm). The “broken” phenomenon of shock waves due to turbulence interaction have reported in numerical studies. This study firstly observed the “broken” phenomenon of the shock wave in experiments. Details of the research are shown in the paper [2]. In the latest experiments, we observed losing of the shock wave front profile. We also developed new model which explain this phenomenon based on the “Riemann problem” [3,4].

These studies revealed that the shape of the shock wave changed significantly as the shock wave progressed in turbulence. We are conducting further research to understand the shock wave behavior in unsteady flows.

The followings are shadowgraph visualization movies of the interaction between the shock wave (moving to the right, shock wave Mach number 1.03) and turbulence (moving to the left, turbulence Mach number 0.024). In this method, changes in density are visualized as changes in brightness.

Interaction length: 65 mm
(at the center of the window)
Interaction length: 1121 mm

*1 Turbulence Mach number Mt: A dimensionless quantity obtained by dividing velocity fluctuation by sound velocity.
*2 Shock Mach number Ms: A dimensionless quantity obtained by dividing a propagating speed of shock wave by sound velocity.

Papers related to this research
[1] T. Tamba, T. M. Nguyen, K. Takeya, T. Harasaki, A. Iwakawa, A. Sasoh “Counter-Driver Shock Tube,” Shock Waves 25, 667-674 (2015). doi: 10.1007/s00193-015-0594-z
[2] T. Tamba, G. Fukushima, M. Kayumi, A. Iwakawa, and A. Sasoh. “Experimental investigation of the interaction of a weak planar shock with grid turbulence in a counter-driver shock tube,” Phys. Rev. Fluids 4, 073401 (2019). doi: 10.1103/PhysRevFluids.4.073401

[3] G. Fukushima, J. Wei, S. Ogawa, J. Hagiwara, Y. Nakamura and A. Sasoh, “Losing the shock wave front profile due to interaction with turbulence,” Fluid Dyn. Res. 53(2), 025504 (2021). doi: 10.1088/1873-7005/abeda4

[4] G. Fukushima, S. Ogawa, J. Wei, Y. Nakamura and A. Sasoh, ” Impacts of grid turbulence on the side projection of planar shock waves,” Shock Waves 31, 101-115(2021). doi: 10.1007/s00193-021-01000-2

 

Stop Rotation of Debris by Laser Ablation

Fragments of the rocket components and the satellites, the so-called “space debris”, are threatening the safety in earth orbit. It is said that more than 500 thousand of debris is orbiting with extremely high speed (7.9 km/s, for example). So, space debris mitigation is one of the most urgent problems in the space development field.
 In our Laboratory, the technique of deorbiting debris by laser ablation is studied. To demonstrate validity of the deorgiting method, we attempted to stop rotation of miniature satellite model by laser irradiation. Rotation of the model is almost terminated with generated impulse of laser ablation.
 

https://youtu.be/IgkuF-fTNaA

News

2022.7.15
  • Gaku Fukushima won “AIAA Computation Fluid Dynamics Best Student Paper Competition 1st Place” at 2022 AIAA AVIATION Forum. (detail, certificate)
    Authors Title
    Gaku Fukushima (Nagoya University), Keiichi Kitamura (Yokohama National University), and Akihiro Sasoh (Nagoya University) On Peculiar Behaviors of Captured Very-Weak Moving Shockwaves
2022.6.24
  • Publication updated.
  • An article written by Daisuke Ichihara et al. was published on Shock waves.(detail)
    Title

    Geometrical matching in remote in-tube shock compression by an unsteady jet

2022.6.15
  • Gaku Fukushima won “Nagoya University outstanding graduate student award”. (detail)
2022.5.18
  • We received a donation from Daisuke Takagi, a graduate of 2010. The donation will be used for new research (Takagi project) by the students in the laboratory. The application deadline for the Takagi project is 7/1.
2021.4.13
  • We received a donation from Daisuke Takagi, a graduate of 2010. The donation will be used for new research (Takagi project) by the students in the laboratory. The application deadline for the Takagi project is 9/13.
2021.4.13
  • Publication updated.
  • An article written by Gaku Fukushima et al. was published on Fluid Dynamics Research(detail)
Title

Losing the shock wave front profile due to interaction with turbulence

2021.1.8
  • Publication updated.
  • An article written by Yusuke Nakamura et al. was published on Experiment in Fluids(detail)
Title

Speckle beam-oriented schlieren technique

2020.6.28
  • Publication updated.
  • An article written by Gaku Fukushima et al. was published on Shock Waves(detail)
Title

Influence of cellophane diaphragm rupture processes on the shock wave formation in a shock tube

2020.5.4
  • Publication updated.
  • An article written by Yusuke Katagiri et al. was published on TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES(detail)
Title

Boundary Effect on the Laser-ablation Impulse Characteristics of a Flat-Head Cylinder

2020.4.25
  • Publication updated.
  • An book written by Prof. Akihiro Sasoh was published. (detail)
    Title

    Compressible Fluid Dynamics and Shock Waves

2020.4.8
2020.3.4
  • Prof. Akihiro Sasoh was awarded 2019 Glass Memorial Lecture Award (GLMA) at Shock Wave Research Society of Japan. (detail)
2020.2.4
2020.2.3
  • Publication updated.
  • An article written by Daisuke Ichihara et al. was published on JOURNAL OF PROPULSION AND POWER(detail)
Title

High-Specific-Impulse Electrostatic Thruster with Argon Propellant

2019.11.14
  • Publication updated.
  • An article written by Daisuke Ichihara et al. was published on JOURNAL OF PROPULSION AND POWER(detail)
Title

Central and External Cathode Operations in a Diverging-Magnetic-Field Electrostatic Thruster

2019.11.14
  • Publication updated.
  • An article written by Manabu Myokan et al. was published on AIAA journal. (detail)
Title

Repetitive Energy Deposition at a Supersonic Intake in Subcritical and Buzz Modes

2019.10.26
  • Gaku Fukushima(M2) was awarded Chubu branch lecture award at 17th JSFM Chubu branch symposium.
    Authors Title
    Gaku Fukushima, Shingo Ogawa, Wei Jiaxi, Yusuke Nakamura, Akihiro Sasoh 対向衝撃波管を用いた衝撃波と乱流の干渉実験
2019.8.17
  • Publication updated.
  • An article written by Takahiro Tamba et al. was published on Physical Review Fluids.(detail)
Title

Experimental investigation of the interaction of a weak planar shock with grid turbulence in a counter-driver shock tube

  • An article written by Yusuke Katagiri et al. was published on Physica Scripta.(detail)
Title

Sunflower Effect: Enhancement of laser-pulse-induced impulse in the beam incident direction due to surface undulation

2018.11.24
  • Manabu Myokan(M2) was awarded Chubu branch student award at 55th JSASS Chubu and Kansai branch joint symposium.
Authors Title
Manabu Myokan, Wu Yen Lin, Akiya Kubota, Akira Iwakawa, Akihiro Sasoh エネルギー付加による超音速インテイク性能の向上
2018.10.16
  • Publication updated.
  • An article written by Akihiro Sasoh et al. was published on Acta Astronautica.(detail)
Title

Electrostatic-magnetic-hybrid thrust generation in central–cathode electrostatic thruster (CC–EST)

2018.01.21
  • An article written by Hayato Kasuga et al. was published on TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, AEROSPACE TECHNOLOGY JAPAN.
    Title Operation Characteristics of Applied-Field Magnetoplasmadynamics Thruster Using Hollow Cathode(detail)
2017.11.20
  • An article written by H.S.Pham et al. was published on AIAA Journal.
  • Title Effect of Repetitive Laser Energy Deposition on Supersonic Duct Flows(detail)
2017.10.01
2017.09.04
  • An article written by Akira Iwakawa et al. was published on Transactions of The Japan Society for Aeronautical and Space Sciences.
    Title Mach-number Effect on Supersonic Drag Reduction using Repetitive Laser Energy Depositions over Blunt-Body(detail)
2017.07.26
  • An article written by Daisuke Ichihara et al. was published on Journal of Applied Physics.
    Title Effects of magnetic field profile near anode on ion acceleration characteristics of a diverging magnetic field electrostatic thruster(detail)
2017.07.12
  • An article written by Daisuke Ichihara et al. was published on Acta Astronautica.
    Title Power matching between plasma generation and electrostatic acceleration in helicon electrostatic thruster(detail)
2017.06.28
  • An article written by H. S. Pham et al. was published on AIAA Journal.
    Title Impacts of Laser Energy Deposition on Flow Instability over Double-Cone Model(detail)
2017.06.06
  • An article written by Akihiro Sasoh et al. was published on AIP advances.
    Title Electrostatic/magnetic ion acceleration through a slowly diverging magnetic nozzle between a ring anode and an on-axis hollow cathode(detail)
2017.04.30
  • Takahiro Tamba(D3) was awarded Japan Explosion Society Award 2016.
    Title Mathematical model of interaction between blast wave and turbulent flow
    Journal Field experiment of blast wave pressure modulation past a turbulent flow (Detail)
 Past Update is here.