Numerical Study on Acoustic Radiation for Designing Launch-Pad of Advanced Solid Rocket

Tsutsumi, Seiji; Fukuda, Kota; Takaki, Ryoji; Shima, Eiji; Fujii, Kozo; Ui, Kyoichi

doi:10.2514/6.2008-5148

Cited by 22 publications

(8 citation statements)

References 5 publications

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“…Nevertheless, computations on simplified geometries have been attempted in a view to understand basic flow physics and noise generation mechanisms of due to the interactions of jet with the deflector. Computational studies by Tsutsumi [43] showed that unsteadiness from the jet interactions with the bowl-shaped deflector cause pressure waves that are directed back towards the vehicle due to its geometry. A recent study by Tsutsumi [44], attempted to analyze the acoustic field from a jet impinging on different deflector shapes with the nozzle exit plane maintained at a fixed distance.…”

Section: Introductionmentioning

confidence: 99%

Flow Field and Acoustic Investigations of the Launch Vehicle Environment during Lift-off

Karthikeyan¹,

Venkatakrishnan²

2015

21st AIAA/CEAS Aeroacoustics Conference

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During the lift-off phase, a launch vehicle is exposed to severe acoustic loads which are detrimental to the vehicle structure as well as sensitive equipment onboard. Any effort to reduce these loads is beneficial, as it reduces the additional strengthening of the vehicle structure and consequently the weight of the vehicle itself. The design of the jet deflector and launch environment such as launch platform influences the noise levels significantly. Any modifications to them for achieving noise reduction is quite challenging as it should take into account, the factors other than acoustics, such heat transfer, ease of vehicle access etc. Existing literature dealing with simplified jet impingement do not replicate the launch scenario faithfully, ignoring contributions from the factors like launch platform geometry and cutouts in launch platform. Very little is known on the level of impact of these factors on the propagation of noise from the jet exhaust. The present study attempts to address this by investigating the influence of presence of a launch platform with cut-outs on the acoustic field and flow field around a generic launch vehicle exhausting on a realistic jet deflector. The measurements include flow field visualization using shadowgraphy and aeroacoustic measurements using microphones in the near and far-field.

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Section: Introductionmentioning

confidence: 99%

Flow Field and Acoustic Investigations of the Launch Vehicle Environment during Lift-off

Karthikeyan¹,

Venkatakrishnan²

2015

21st AIAA/CEAS Aeroacoustics Conference

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“…Nomenclature a = speed of sound in the gas a P = speed of sound in the liquid phase T 0 = mean temperature in the gas T = perturbation of temperature in the gas T P = temperature in the liquid phase P = perturbation of pressure in the gas P 0 = mean pressure in the gas Pv = partial pressure of the vapor (currently, Lecturer, Tokai University, School of engineering, Department of Aeronautics and Astronautics) 2 Engineer, JAXA s Engineering Digital Innovation (JEDI) center, AIAA Senior Member. 3 Associate Senior Engineer, JAXA s Engineering Digital Innovation (JEDI) center, AIAA Senior Member. 4 Associate professor, Institute of Space and Astronautical Science (ISAS), AIAA Senior Member.…”

mentioning

confidence: 99%

“…Since the acoustic wave causes the acoustic load on the payload, prediction and reduction of the acoustics level around launch vehicles at liftoff is quite important design factor taken into consideration early in the design process of the launch-pad. As for the understanding fundamental mechanism of the acoustic generation at lift-off of launch vehicles, the authors have applied Computational Fluid Dynamics (CFD) to reveal the generation and propagation mechanism of the acoustic waves from Japanese launch vehicles, such as the H-IIA launch vehicle, the M-V launch vehicle, and now studying the Epsilon launch vehicle [2][3] . From these results, the detail of the acoustic generation and propagation mechanism has been cleared.…”

mentioning

confidence: 99%

Examination of Sound Suppression by Water Injection at Lift-off of Launch Vehicles

Fukuda

Tsutsumi

Shimizu

et al. 2011

17th AIAA/CEAS Aeroacoustics Conference (32nd AIAA Aeroacoustics Conference)

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Analytical investigation of noise suppression effect of water injection to exhaust plume from rocket motors was carried out. The results showed acoustic absorption by water droplets, acoustic scatter by water droplets, absorption through air, and water curtain effect increase as frequency becomes high. It was also confirmed that acoustic absorption by water droplets has the most significant effects among the four effects. Furthermore, steady 2D-axisymmetric Reynolds-Averaged Navier-Stokes (RANS) simulations of a supersonic free jet were carried out in order to evaluate reduction of jet energy due to water injection. The reduction of the acoustic source strength along the jet axis was evaluated considering the difference of r 2 k 7/2 value between with and without water injection. The far field sound power level (SPL) was analyzed using an empirical prediction method, NASA SP-8072 [1] and compared to sub-scale motor test data. The strength of the acoustic source power along the jet axis was set based on the reduction rate of the r 2 k 7/2 value due to water injection and the propagation to the far filed points was analyzed based on the NASA SP-8072 [1] . The results showed that the water injection effect can be reasonably evaluated by using both the analytical prediction methodology and the evaluation methodology of reduction of the jet energy based on the change of r 2 k 7/2 . Nomenclature a = speed of sound in the gas a P = speed of sound in the liquid phase T 0 = mean temperature in the gas T = perturbation of temperature in the gas T P = temperature in the liquid phase P = perturbation of pressure in the gas P 0 = mean pressure in the gas Pv = partial pressure of the vapor Pv e = equilibrium saturation pressure r = mean density of the gas r P0 = mean density of the liquid r P = perturbation of density of the liquid r V0 = mean density of the vapor u = perturbation of velocity in the gas phase u P = perturbation of velocity in the liquid phase k V = mass rate of vapor to the gas k P = mass rate of liquid to the gas C p = specific heat of gas at constant pressure 1 Researcher, JAXA s Engineering Digital Innovation (JEDI) center, AIAA Senior Member. 092407 2 r p = water droplet radius C v = specific heat of gas at constant volume l = thermal conductivity of gas m = kinematic viscosity of the gas h l = latent heat of vaporization of the liquid D p = diameter of water droplet q = angle from jet axis r= distance from the center of nozzle exit D e = diameter of nozzle exit k = turbulent kinetic energy (TKE) X = distance along jet axis from nozzle exit Q p = mass flow rate of exhaust jet Q w = mass flow rate of injected water

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“…14(a), are dominant. [17][18][19][20][21][22] The acoustic wave due to the jet impingement propagates omnidirectionally from the vicinity of the impingement region, and determines the acoustic environment surrounding the vehicle. On the other hand, the Mach wave radiation from the wall jet has a strong directivity at roughly 50 degree from the wall jet axis, so that the effect on the vehicle must be small.…”

Section: Acoustic Design Of Launch Padmentioning

confidence: 99%

Study on Acoustic Prediction and Reduction of Epsilon Launch Vehicle at Liftoff

Tsutsumi

Ishii

et al. 2015

Journal of Spacecraft and Rockets

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Numerical Study on Acoustic Radiation for Designing Launch-Pad of Advanced Solid Rocket

Cited by 22 publications

References 5 publications

Flow Field and Acoustic Investigations of the Launch Vehicle Environment during Lift-off

Flow Field and Acoustic Investigations of the Launch Vehicle Environment during Lift-off

Examination of Sound Suppression by Water Injection at Lift-off of Launch Vehicles

Study on Acoustic Prediction and Reduction of Epsilon Launch Vehicle at Liftoff

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