Off-Design Sonic Boom Performance for Low-Boom Aircraft

Lazzara, David S.; Magee, Todd; Shen, Hao; Mabe, James H.

doi:10.2514/6.2019-0606

Cited by 10 publications

(5 citation statements)

References 23 publications

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“…the following equation is obtained after rearrangement of equation ( 21) 4 The relationship between Kirchhoff stress t and Cauchy stress s is…”

Section: Additive Decomposition Of Logarithmic Strainmentioning

confidence: 99%

“…Since the discovery of shape memory effect, SMAs have been extensively investigated as sensors and actuators towards building smart systems integrated with adaptive and morphing features [2,3]. Recently, aerospace researchers have considered to use the SMA-based actuators to reconfigure the shape of a supersonic aircraft to meet the noise and efficiency requirements in response to the real-time changing ambient environment, which has the great potential to realize a commercially viable overland civil supersonic flight in the near future [4,5].…”

Section: Introductionmentioning

confidence: 99%

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A three-dimensional constitutive model for the martensitic transformation in polycrystalline shape memory alloys under large deformation

Baxevanis

Lagoudas

2019

Smart Mater. Struct.

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This work presents a three-dimensional constitutive model for the martensitic transformation in polycrystalline Shape Memory Alloys (SMAs) under large deformation. By utilizing the logarithmic strain and rate, the model is able to account for large strains and rotations that SMA-based components may undertake, but also resolves the artificial stress errors caused by the non-integrable objective rates that are widely used in current commercial finite element software. The model is developed through classical thermodynamic laws combined with the standard Coleman-Noll procedure. The scalar martensitic volume fraction and the second-order transformation strain tensor are chosen as the internal state variables to capture the material response exhibited by polycrystalline SMAs. A detailed implementation procedure of the proposed model is described through a user-defined material subroutine. Numerical experiments considering SMA components including a bar, a beam, a torque tube and a solid flexible structure under stress/thermally-induced phase transformations are investigated via the proposed model, and the results under cyclic loading are compared against the predictions provided by the Abaqus nonlinear solver. The development framework of the proposed model and its implementation procedure can be extended to incorporate other nonlinear phenomena exhibited by SMAs, such as transformation-induced plasticity, viscoplasticity, and damage under large deformation.

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“…the following equation is obtained after rearrangement of equation ( 21) 4 The relationship between Kirchhoff stress t and Cauchy stress s is…”

Section: Additive Decomposition Of Logarithmic Strainmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

A three-dimensional constitutive model for the martensitic transformation in polycrystalline shape memory alloys under large deformation

Baxevanis

Lagoudas

2019

Smart Mater. Struct.

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“…A vehicle's Mach, angle of attack, and the atmospheric profile between the aircraft and the ground have all been shown to have a significant impact on perceived loudness. To minimize the impact of the adverse conditions on perceived noise small modifications to the geometry of the vehicle's outer mold line (OML) have been shown restore the vehicle to a low boom state [5].…”

Section: Introductionmentioning

confidence: 99%

Actuation Fatigue and Lifetime Cycling of Nitihf High Temperature Shape Memory Alloys

Mabe,

Demblon,

Karaman

2023

10th ECCOMAS Thematic Conference on Smart Structures and Materials

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As part of NASA's University Leadership Initiative (ULI) program a team of researchers led by Texas A&M University are investigating compact and lightweight shape memory alloy (SMA) actuators to drive real time geometry changes in order to minimize the boom signature of supersonic vehicles across all aircraft configurations and atmospheric conditions. The NiTiHf system of high temperature shape memory alloys (HTSMA) was selected as the baseline alloy for the project. In addition to the higher transformation temperatures the nickel rich NiTiHf compositions possess a significantly improved thermomechanical stability compared to NiTi alloys, while maintaining a comparably high work output. This paper describes the testing done to quantify actuation cycling limits and failure modes of these materials. Alloy composition, microstructure, and thermomechanical cycling parameters have all been shown to affect the extended cycling behavior and lifetime performance of HTSMAs. The impact of each of these parameters on actuation fatigue and extended cycling performance are presented. The most effective and practical method to extend both structural lifetime and stabilize the actuation performance of an HTSMA component is shown to be partial thermal cycling. An order of magnitude increase in actuation fatigue lifetime has been successfully achieved by limiting transformation per cycle through partial heating under load. More importantly, actuation work was kept nearly constant by increasing stress while thermally limiting actuation strain. This has been shown to be more effective at increasing the fatigue life than reducing actuation stress level alone, yielding 5 to 10 times the relative improvement in fatigue life.

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“…The International Council on Clean Transport (ICCT) study the environmental noise and emissions standards of supersonic transport in the SUAVE (Stanford University Aerospace Vehicle Environment) environment and suggest the policymakers to establish new environmental standards for supersonic transport 16 . For off-design conditions, Lazzara et al 17 reveals the perturbations of angle of attach and Mach number would have an impact on the ground boom signature. This paper intends to show the feasibility of low-boom low-drag supersonic designs in a more general multidisciplinary perspective, to study the fuel conservation operating scenarios, and to explore the sonic boom avoidance or constrained overland flight profiles.…”

Section: Introductionmentioning

confidence: 99%

Design and operational assessment of a low-boom low-drag supersonic business jet

Sun

Smith

2021

Proceedings of the Institution of Mechanical Engineers, Part G:

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There has been a worldwide interest to develop a supersonic business jet (SSBJ) for a minimum range of 4000 nm with low sonic boom intensity and high fuel efficiency. An SSBJ design model is developed in the GENUS aircraft conceptual design environment. With the design model, a low-boom low-drag SSBJ concept is designed and optimized. This article studies the design concept for its operational performances. The sustained supersonic cruise flight is studied to find out the fuel-efficient Mach number and altitude combinations. The combined supersonic and subsonic cruise flight scenarios are studied to evaluate the feasibility of boom-free flight routes. The one-stop supersonic cruise flight scenario is studied to compare the fuel consumption and time advantage over subsonic airliners. The off-design sonic boom intensity is studied to explore the operational space assuming there would be a sonic boom intensity limit in the future. Through the studies, it is revealed that there is a corresponding most fuel-efficient operating altitude for a specific cruise Mach number. To operate the aircraft near the cutoff Mach number leads to both increases in the fuel consumption (6.3%–8.1%) and the mission time (11.7%–13.1%). The business-class supersonic transport (231 g/PAX/km) consumes nearly three times fuel as the economic-class supersonic transport (77 g/PAX/km), which is still far more than the economic-class subsonic transport (20 g/PAX/km). Off-design sonic boom intensity studies reveal different trends against the common understanding: the sonic boom intensity does not necessarily decrease as the altitude increases; the sonic boom intensity does not necessarily decrease as the Mach number decreases.

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Off-Design Sonic Boom Performance for Low-Boom Aircraft

Cited by 10 publications

References 23 publications

A three-dimensional constitutive model for the martensitic transformation in polycrystalline shape memory alloys under large deformation

A three-dimensional constitutive model for the martensitic transformation in polycrystalline shape memory alloys under large deformation

Actuation Fatigue and Lifetime Cycling of Nitihf High Temperature Shape Memory Alloys

Design and operational assessment of a low-boom low-drag supersonic business jet

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