Development of the Gulfstream Quiet Spike TM for Sonic Boom Minimization

Howe, D.; Simmons, Frank; Freund, Don

doi:10.2514/6.2008-124

Cited by 37 publications

(20 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Recent studies focus on tailoring shock waves to achieve desired compression of the incoming flow. Gulfstream's quiet spike program (Howe et al [16]) uses a long telescopic fuselage extension to alter the N-wave pressure signature by breaking down the strong bow shock in front of the canopy into a series of weaker shock waves upstream of the fuselage such that the terminal bow shock becomes weaker. The fuselage extension employed also ensures that these weaker shocks remain parallel in the farfield, hence not coalesce to avoid the possibility of a sonic boom.…”

Section: Introductionmentioning

confidence: 99%

Flow Field Characteristics of Oblique Shocks Generated Using Microjet Arrays

Ali

Ahmed

Kumar

et al. 2014

International Journal of Flow Control

View full text Add to dashboard Cite

High-momentum steady microjet arrays are used to generate single and/or multiple oblique shocks in a supersonic crossflow. The properties of these microjet-generated shocks can be tailored to be parallel or coalescing, depending on the application, by adjusting the pressure ratio. Building upon the results of prior studies, flow field measurements using Particle Image Velocimetry were obtained. The velocity field clearly shows the effect of the microjet-generated oblique shocks on the flow field. Changes in the velocity field across the oblique shock and the expansion fan are also clearly seen from these results. The strength of the microjet-generated shocks was found to be constant along the length of the shock. Properties of microjet-generated shocks are compared with oblique shocks using a ramp and differences and similarities between the two are found. Flow properties due to multiple parallel and coalescing shocks were also investigated to better understand the behavior of such flow features introduced using fluidic micro-actuators.

show abstract

Section: Introductionmentioning

confidence: 99%

Flow Field Characteristics of Oblique Shocks Generated Using Microjet Arrays

Ali

Ahmed

Kumar

et al. 2014

International Journal of Flow Control

View full text Add to dashboard Cite

show abstract

“…Extensive efforts have focused on the fundamental design of the supersonic aircraft shape, which produces a lower level of the near-field pressure disturbance below the supersonic aircraft at a high altitude. [1][2][3][4][5][6] Evaluation methods of the sonic boom on the ground from the near-field one are required to confirm the validity of the shape so designed. Therefore, it is desirable to calculate the modification of the pressure disturbance generated by the aircraft during the propagation in an atmospheric air to the ground theoretically.…”

Section: Introductionmentioning

confidence: 99%

A unified approach to an augmented Burgers equation for the propagation of sonic booms

Yamamoto¹,

Hashimoto

Aoyama

et al. 2015

The Journal of the Acoustical Society of America

View full text Add to dashboard Cite

Nonlinear propagation through a relaxing atmosphere of pressure disturbances extracted from a computational fluid dynamics (CFD) solution of the flow around a supersonic aircraft is simulated using an augmented Burgers equation. The effects of nonlinearity, geometrical spreading, atmospheric inhomogeneity, thermoviscous attenuation, and molecular vibration relaxation are taken into account. The augmented Burgers equation used for sonic boom propagation calculations is often solved by the operator splitting method, but numerical difficulties arise with this approach when dissipation is not effective. By re-examining the solution algorithms for the augmented Burgers equation, a stable method for handling the relaxation effect has been developed. This approach can handle the Burgers equation in a unified manner without operator splitting and, therefore, the resulting scheme is twice as fast as the original one. The approach is validated by comparing it with an analytical solution and a detailed CFD of dispersed plane wave propagation. In addition, a rise time prediction of low-boom supersonic aircraft is demonstrated.

show abstract

“…The Shaped Sonic Boom Demonstration aircraft, which creates the trapezoid pressure wave, was designed by modifying the F-5E fighter aircraft [2,3]. Cowart and Grindle [4] and Howe et al [5] proposed and demonstrated another approach that they called Quiet Spike; they used a multistage nose to propagate several sets of a compression wave and expansion fan. Because the peak overpressure values (either positive or negative) in each sets are similar in level, their coalescences are delayed even in far fields.…”

mentioning

confidence: 99%