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All sourcesNASA NTRSDOE OSTI
NASA NTRSDate not supplied

Using Global Market Demand Analysis to Guide Conceptual Design of Low-Boom Supersonic Transports

This paper uses a mathematical framework to identify the interdependencies of key variables in supersonic transportation demand analysis. The existing quantitative models for supersonic transportation demand analysis are compared for consistency in modeling the interdependencies. Unlike other quantitative models, the Low-Boom Systems Analysis Model (LBSAM2) can propagate important design characteristics of a supersonic transport aircraft concept to the level of economic metrics (such as the number of future supersonic passengers), with a consistent coupling of the market demand analysis, detailed mission analysis, and low-boom constraint. This allows the use of the detailed demand analysis results from LBSAM2 to maximize the economic viability of a supersonic transport aircraft by finding favorable system-level trades between weight, range, fuel burn, and assumed sonic boom ground noise limit for supersonic overland flight. In this paper, LBSAM2 is integrated with conceptual low-boom design to improve the economic viability of low-boom supersonic transport aircraft. A brief discussion of uncertainties in the LBSAM2 analysis is also included, focusing on their impacts on the relative economic advantages between low-boom concepts.

Consistent coupling of disciplinary analyses↗
NASA NTRSDate not supplied

Using Global Market Demand Analysis to Guide Conceptual Design of Low-Boom Supersonic Transports

This paper uses a mathematical framework to identify the interdependencies of key variables in supersonic transportation demand analysis. The existing quantitative models for supersonic transportation demand analysis are compared for consistency in modeling the interdependencies. Unlike other quantitative models, the Low-Boom Systems Analysis Model (LBSAM2) can propagate important design characteristics of a supersonic transport aircraft concept to the level of economic metrics (such as the number of future supersonic passengers), with a consistent coupling of the market demand analysis, detailed mission analysis, and low-boom constraint. This allows the use of the detailed demand analysis results from LBSAM2 to maximize the economic viability of a supersonic transport aircraft by finding favorable system-level trades between weight, range, fuel burn, and assumed sonic boom ground noise limit for supersonic overland flight. In this paper, LBSAM2 is integrated with conceptual low-boom design to improve the economic viability of low-boom supersonic transport aircraft. A brief discussion of uncertainties in the LBSAM2 analysis is also included, focusing on their impacts on the relative economic advantages between low-boom concepts.

Equilibrium state of supersonic market↗
NASA NTRS1978

Supersonic transport

An aircraft of supersonic transport configuration is described, featuring thrust vectoring in conjunction with wing apex segments used as canard surfaces during takeoff, landing, and low-speed flight. The angle of incidence of the wing apex segments, when the segments were functioning as canard surfaces, was variable with respect to the aircraft angle of attack. The wing apex segments furthermore formed a portion of the main wing panel swept leading edge when not functioning as canard surfaces. The combination of thrust vectoring and deployable wing apex segments resulted in increased aircraft range and improved low speed longitudinal stability while providing acceptable takeoff length capabilities.

Coe, P. L., Jr.↗
NASA NTRS2018

Navier-Stokes Equations Based Aeroelasticity of Supersonic Transport Including Short Period Oscillations

There is renewed interest in developing new supersonic transports after the discontinuation of the Concorde supersonic jet, which was mostly limited for flights over trans-oceanic routes due to the severe noise of the sonic boom. In order to avoid the sonic boom, more slender configurations, such as the Low Boom Flight Demonstrator (LBFD) configuration, are being considered. The aeroelastic characteristics of these new supersonic transports can significantly differ from conventional aircraft. Both rigid and flexible body modes can play a significant role in aeroelastic stability. For unconventional configurations, such as aircraft with forward swept wings, the short period oscillation (SPO) has been found to significantly impact the aeroelastic response. SPO can occur due to unanticipated events such as gusts, abrupt maneuvering, etc. During the design of the Concorde, the effects of SPO was considered in detail, though its impact is not publically disclosed. Assuring stability of supersonic aircraft, particularly during descent from the supersonic Mach regime to the transonic regime, is critical. An aircraft can deviate from its normal descent trajectory due to coupling between flows and body motions. The effect of SPO needs to be considered in aeroelastic responses. Preliminary studies using quasi-steady aerodynamics show that the presence of SPO can lead to unstable response. The well-established Reynolds Averaged Navier-Stokes (RANS) equations, which are computationally feasible with current supercomputers, have been in use for aeroelastic computations for the last three decades. Recently, such efforts have begun to include trajectory motions; for instance, the effect of phugoid motion on stability is studied in Ref. 9 using the RANS equations. In this paper, the effect of SPO on aeroelastic responses of a typical supersonic transport is studied.

Guruswamy, Guru↗
NASA NTRS1965

Effects of the Air Traffic Control System on the Supersonic Transport

A study of the problems anticipated with the introduction of the supersonic transport into the air traffic control system indicated that supersonic transport design allowances for time and fuel for maneuvering during climbouts may not be sufficient, that there is a greater communications-navigation work- load for the supersonic transport than for the subsonic jet transport during descent, and that use of a flight director to command pitch control guidance for the pilot would be helpful.

Norman S. Silsby↗
NASA NTRS1973

Toward a second-generation supersonic transport.

A number of promising avenues of research and development are considered in relation to an advanced supersonic transport which has improved range/payload characteristics and lower airport noise and sonic boom than current-generation supersonic transports. The prospects for advanced technology suggest that a high lift-to-drag-ratio configuration incorporating advanced materials and control concepts and utilizing a variable-cycle engine or perhaps an advanced dry turbojet, will yield an advanced supersonic transport which is economically viable and socially acceptable. Hydrogen fuel offers great promise for future supersonic aircraft, however, the formidable problems associated with the use of such fuel probably precludes its use on any near term second-generation supersonic transport. The state of technology in some of the areas discussed is not very far advanced and, consequently, a major effort will be required to bring these technologies to a state of readiness on a timely basis.

Loftin, L. K., Jr.↗
NASA NTRS2021

Simulation of Landing and Take-Off Noise for Supersonic Transport Aircraft at a Conceptual Design Fidelity Level

The German Aerospace Center has launched an internal project to assess the noise impact associated with supersonic transport aircraft during approach and departure. A dedicated simulation process is established to cover all relevant disciplines, i.e., aircraft and engine design, engine installation effects, flight simulation, and system noise prediction. The core of the simulation process is comprised of methods at the complexity and fidelity level of conceptual aircraft design, i.e., typical overall aircraft design methods and a semi-empirical approach for the noise modeling. Dedicated interfaces allow to process data from high fidelity simulation that will support or even replace initial low fidelity results in the long run. All of the results shown and discussed in this study are limited to the fidelity level of conceptual design. The application of the simulation process to the NASA 55t Supersonic Technology Concept Aeroplane, i.e., based on non-proprietary data for this vehicle, yields similar noise level predictions when compared to the published NASA results. This is used as an initial feasibility check of the new process and confirms the underlying methods and models. Such an initial verification of the process is understood as an essential step due to the lack of available noise data for supersonic transport aircraft in general. The advantageous effect of engine noise shielding on the resulting system noise is demonstrated based on predicted level time histories and certification noise levels. After this initial verification, the process is applied to evaluate a conceptual supersonic transport design based on a PhD thesis with two engines mounted under the wing, which is referred to as aircraft TWO. Full access to this vehicle’s design and performance data allows to investigate the influence of flight procedures on the resulting noise impact along approach and departure. These noise results are then assembled according to proposed Federal Aviation Agency regulations in their Notice of Proposed Rulemaking, e.g., speed limitations, for Supersonic transport noise certification and the regulations from Noise Chapters of the Annex 16 from the International Civil Aviation Organization in order to evaluate the resulting levels as a function of the flight procedure.

noise↗
NASA NTRS1985

Study of an efficient long-range Mach 2.7 supersonic transport configuration concept

A long range Mach 2.7 supersonic transport configuration concept was studied utilizing linear theory methods. The configuration was sized to carry 290 passengers 6,000 nautical miles nonstop. The final configuration has a maximum takeoff gross weight of 687,200 pounds, a wing loading of 69.8 lbf/sq.ft. and a thrust weight ratio of .278. The most significant result is that a significantly improved trimmed maximum lift drag ratio of 11.04 can be obtained for a supersonic transport at Mach 2.62 and 55,000 feet.

Gall, P. D.↗
NASA NTRS1977

Judgements of relative noisiness of a supersonic transport and several commercial-service aircraft

Two laboratory experiments were conducted on the relative noisiness of takeoff and landing operations of a supersonic transport and several other aircraft in current commercial service. A total of 96 subjects made noisiness judgments on 120 tape-recorded flyover noises in the outdoor-acoustic-simulation experiment; 32 different subjects made judgments on the noises in the indoor-acoustic-simulation experiment. The judgments were made by using the method of numerical category scaling. The effective perceived noise level underestimated the noisiness of the supersonic transport by 3.5 db. For takeoff operations, no difference was found between the noisiness of the supersonic transport and the group of other aircraft for the A-weighted rating scale; however, for landing operations, the noisiness of the supersonic transport was overestimated by 3.7 db. Very high correlation was found between the outdoor-simulation experiment and the indoor-simulation experiment.

Powell, C. A.↗
NASA NTRS2000

A Qualitative Piloted Evaluation of the Tupolev Tu-144 Supersonic Transport

Two U.S. research pilots evaluated the Tupolev Tu-144 supersonic transport aircraft on three dedicated flights: one subsonic and two supersonic profiles. The flight profiles and maneuvers were developed jointly by Tupolev and U.S. engineers. The vehicle was found to have unique operational and flight characteristics that serve as lessons for designers of future supersonic transport aircraft. Vehicle subsystems and observed characteristics are described as are flight test planning and ground monitoring facilities. Maneuver descriptions and extended pilot narratives for each flight are included as appendices.

Rivers, Robert A.↗
NASA NTRS1975

Variable cycle engines for advanced supersonic transports

Variable Cycle Engines being studied for advanced commercial supersonic transports show potential for significant environmental and economic improvements relative to 1st generation SST engines. The two most promising concepts are: a Variable Stream Control Engine and a Variable Cycle Engine with a rear flow-control valve. Each concept utilizes variable components and separate burners to provide independent temperature and velocity control for two coannular flow streams. Unique fuel control techniques are combined with cycle characteristics that provide low fuel consumption, similar to a turbojet engine, for supersonic operation. This is accomplished while retaining the good subsonic performance features of a turbofan engine. A two-stream coannular nozzle shows potential to reduce jet noise to below FAR Part 36 without suppressors. Advanced burner concepts have the potential for significant reductions in exhaust emissions. In total, these unique engine concepts have the potential for significant overall improvements to the environmental and economic characteristics of advanced supersonic transports.

Howlett, R. A.↗