Sonic boom reduction through aircraft design and operation

Author(s):  
A. SEEBASS ◽  
A. GEORGE
Keyword(s):  
2007 ◽  
Vol 111 (1126) ◽  
pp. 761-776 ◽  
Author(s):  
H. Smith

Abstract Key issues relating to the Supersonic Business Jet (SBJ) concept are reviewed with the intent to assess the readiness of enabling technologies and hence the concept itself. The multidisciplinary nature of aircraft design precludes an in-depth analysis of each specific aspect, which could individually be the subject of a separate discipline review, hence an overview is presented. The review looks at the market, environmental issues, with particular reference to the sonic boom phenomenon & solutions, technological issues, including prediction methods, flight testing, systems, certification and interested aerospace companies and design organisations. It is apparent that the need to reduce the sonic boom signature is vital if the vehicle is to be permitted to operate over land and hence be economically viable. It is clear that sonic boom acceptability requirements must be set if resources are to be effectively focused and designs are to converge. Despite this challenge, considerable investment is aimed at de-risking many of the enabling technologies and raising readiness levels. Many technologies are moving beyond theoretical and numerical analysis into the experimental and flight test domains. Collaboration between the civil and military sectors is increasing. Clearly, supersonic air travel is not an efficient means of personal conveyance; however, concerns for the environment are difficult to balance against the ‘value of time’ benefits offered by the SBJ concept. Air travel, of which this is a specialised form, is important to the global economy. Continued effort in the areas of human factors, customer demand and certification & requirements would be beneficial.


2014 ◽  
Vol 51 (2) ◽  
pp. 502-510 ◽  
Author(s):  
Sriram K. Rallabhandi ◽  
Eric J. Nielsen ◽  
Boris Diskin
Keyword(s):  

Author(s):  
Yicheng Sun ◽  
Howard Smith

AbstractThis paper introduces a supersonic transport aircraft design model developed in the GENUS aircraft conceptual design environment. A conceptual design model appropriate to supersonic transports with low-to-medium-fidelity methods are developed in GENUS. With this model, the authors reveal the relationship between the sonic boom signature and the lift and volume distributions and the possibility to optimise the lift distribution and volume distribution together so that they can cancel each other at some region. A new inspiring design concept—sonic boom stealth is proposed by the authors. The sonic boom stealth concept is expected to inspire the supersonic aircraft designers to design low-boom concepts through aircraft shaping and to achieve low ground impacts. A family of different classes of supersonic aircraft, including a single-seat supersonic demonstrator (0.47 psf), a 10-passenger supersonic business jet (0.90 psf) and a 50-seat supersonic airliner (1.02 psf), are designed to demonstrate the sonic boom stealth design principles. Although, there are challenges to balance the volume with packaging and control requirements, these concepts prove the feasibility of low-boom low-drag design for supersonic transports from a multidisciplinary perspective.


1980 ◽  
Vol 17 (3) ◽  
pp. 182-186 ◽  
Author(s):  
Robert J. Mack ◽  
Christine M. Darden
Keyword(s):  

Author(s):  
Shaowei Liu ◽  
Junqiang Bai ◽  
Peixun Yu ◽  
Bao Chen ◽  
Boxiao Zhou

It is key points to improve the aerodynamic efficiency and decrease the sonic-boom intensity for the supersonic aircraft design. Sonic-boom prediction method with high precision combining the near-field sonic-boom prediction based on Reynolds-Averaged Navier-Stokes equations and the far-field sonic-boom prediction based on waveform parameter method is firstly established. Then the gradient of sonic boom with respect to the design variables is calculated by the finite difference method and is combined with the gradient of the aerodynamic object by the discrete adjoint technique, acting as the gradient of the weighed object function. Assembling two gradients, the optimization system couples Free Form Deform method、the dynamic mesh technique based on Inverse Distance Weighting interpolation method、the gradient-based optimization algorithm based on the sequential quadratic programming. Using the aerodynamic optimization system considering the sonic boom intensity, the paper conducts a nose angle deflection optimization design and an elaborate aerodynamic optimization including huge design variables and constraints on a supersonic business jet, while the optimization objects are the weighed object and the supersonic cruise drag coefficient. The results show that the nose is deflected downward and the shock wave pattern is changed, leading to a lower far-field maximum overpressure; the drag is decreased by 15.8 counts, and the wing load is moved inboard, also, the pressure drag of the outer wing reduces. Meanwhile, the pressure distribution in the outer wing has a weaker adverse pressure gradient and a more gentle pressure recovery. After optimization, the low-drag and low-sonic boom configuration is obtained, which verified the effectiveness of the optimization system.


Author(s):  
David Graham ◽  
John Dahlin ◽  
Juliet Page ◽  
Kenneth Plotkin ◽  
Peter Coen

2009 ◽  
Vol 113 (1149) ◽  
pp. 739-745 ◽  
Author(s):  
T. Cain

Abstract Current sonic boom theory is based on linear midfield solutions coupled with acoustic propagation models. Approximate corrections are made within the theory to account for non-linearities, in particular for the coalescence of compression waves and the formation of weak shocks. A very large adjustment is made to account for the increasing acoustic impedance that the waves encounter as they propagate from the low density air at cruise altitude to the high density air at sea level. Typically this correction reduces the calculated over pressure levels by a factor of three. Here the method of characteristics (MOC) is used to prove that the density gradient within a hydrostatic atmosphere has no direct effect on the propagation or intensity of the wave. However gravity and ambient temperature both affect the wave propagation and the combined pressure level attenuation is not dissimilar to that previously attributed to acoustic impedance. Although the flawed acoustic theory has given reasonable predictions of measured sonic booms, the omission of gravity from the equation of motion and the inclusion of a false impedance modification, makes the model unreliable for prediction of future designs, particularly those focused on boom minimisation. As an aid to quiet supersonic aircraft design, Whitham’s theory is extended to include gravity and ambient temperature variation and shown to be in good agreement with a MOC solution for the real atmosphere.


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