Effect of emerging technology on a convertible, business/interceptor, supersonic-cruise jet

This study was initiated to assess the feasibility of an eight-passenger, supersonic-cruise long range business jet aircraft that could be converted into a military missile carrying interceptor. The baseline passenger version has a flight crew of two with cabin space for four rows of two passenger seats plus baggage and lavatory room in the aft cabin. The ramp weight is 61,600 pounds with an internal fuel capacity of 30,904 pounds. Utilizing an improved version of a current technology low-bypass ratio turbofan engine, range is 3,622 nautical miles at Mach 2.0 cruise and standard day operating conditions. Balanced field takeoff distance is 6,600 feet and landing distance is 5,170 feet at 44,737 pounds. The passenger section from aft of the flight crew station to the aft pressure bulkhead in the cabin was modified for the interceptor version. Bomb bay type doors were added and volume is sufficient for four advanced air-to-air missiles mounted on a rotary launcher. Missile volume was based on a Phoenix type missile with a weight of 910 pounds per missile for a total payload weight of 3,640 pounds. Structural and equipment weights were adjusted and result in a ramp weight of 63,246 pounds with a fuel load of 30,938 pounds. Based on a typical intercept mission flight profile, the resulting radius is 1,609 nautical miles at a cruise Mach number of 2.0

Application of near-term technology to a Mach 2.0 variable-sweep-wing, supersonic-cruise executive jet

The impact of variable sweep wing technology with relaxed static stability requirements on a supersonic-cruise executive jet with transatlantic range was assessed. The baseline vehicle utilized modified, current-technology engines and titanium structures produced with superplastic forming and diffusion bonding; this vehicle meets study requirements for both supersonic-cruise and low-speed characteristics. The baseline concept has a ramp weight of 64,500 pounds with a crew of two and eight passengers. Its Mach 2.0 cruise range is nearly 3,500 nautical miles; its Mach 0.9 cruise range is over 5,000 nautical miles. Takeoff, landing, and balanced field length requirements were calculated for a composite variant and are all less than 5,000 feet

Eddy Current measurement of Fiber Volume Fraction in Metal Matrix Composite Extrusions

The objective of this work was to develop an eddy current method for measuring fiber volume fraction in continuous-fiber metal matrix composites. Because an eddy current measurement can be affected by the spatial distribution of fibers as well as the overall fiber density, the measurement method had to be tolerant of possible variations in spatial distribution that might be encountered in practice. For this reason, the work began with the development of models of the effective resistivity tensor for a composite with an arbitrary fiber distribution and the resulting eddy current probe response [1,2]. The intent was to use these models to help design a measurement method and to test the method for ordered and disordered arrangements of fibers

Eddy current probe design for second-layer cracks under installed fasteners

The United States Air Force has an operational need to reliably detect second-layer cracks around fastener holes in two-layer airframe structures with the fasteners in place. Because access to the second layer is usually not available, the inspection must be performed by placing a probe on the outer surface of the structure and detecting cracks through the first layer. Eddy current methods have been applied to this inspection problem [1–6], and have met with some success; however, much improvement is still needed to achieve the desired sensitivity to cracks and rejection of signals caused by the geometry of the structure under inspection

Eddy Current Detection of Subsurface Cracks in Engine Disk Boltholes

The development of a reliable eddy current inspection system to detect second layer cracks in sleeved engine disk bolt holes poses serious difficulties. This paper discusses some initial results obtained in two separate investigations that are aimed at advancing the state-of-the-art in eddy current detection of subsurface cracks. Both finite element design optimization results of a horseshoe shaped ferrite core probe, and the results of preliminary evaluation of the applicability of electric current perturbation (ECP) technique to the current problem are presented in this paper

Concept development of a Mach 4 high-speed civil transport

A study was conducted to configure and analyze a 250 passenger, Mach 4 High Speed Civil Transport with a design range of 6500 n.mi. The design mission assumed an all-supersonic cruise segment and no community noise or sonic boom constraints. The study airplane was developed in order to examine the technology requirements for such a vehicle and to provide an unconstrained baseline from which to assess changes in technology levels, sonic boom limits, or community noise constraints in future studies. The propulsion, structure, and materials technologies utilized in the sizing of the study aircraft were assumed to represent a technology availability date of 2015. The study airplane was a derivative of a previously developed Mach 3 concept and utilized advanced afterburning turbojet engines and passive airframe thermal protection. Details of the configuration development, aerodynamic design, propulsion system, mass properties, and mission performance are presented. The study airplane was estimated to weigh approx. 866,000 lbs. Although an aircraft of this size is a marginally acceptable candidate to fit into the world airport infrastructure, it was concluded that the inclusion of community noise or sonic boom constraints would quickly cause the aircraft to grow beyond acceptable limits using the assumed technology levels

Effect of advanced technology and fuel efficient engine on a supersonic-cruise executive jet with a small cabin

An analytical study of a supersonic-cruise, executive, jet aircraft indicated the effects of using advanced technology. The twin-engine, arrow-wing vehicle was configured with a cabin of minimum practical size to hold one pilot, eight passengers, and their baggage. The primary differences between this configuration that of a previous report were the reduction in cabin size and the use of engines that are more fuel-efficient. Both conceptual vehicles are capable of forming the same mission. The current vehicle has a range of 3,350 nautical miles at Mach 2.3 cruise and 2,700 nautical miles at Mach 0.9. The concept description includes configuration definition, aerodynamic and propulsion-system characteristics, and mass properties. Performance analyses are documented for intercontinental and transcontinental flight profiles. In the latter case, a reduction in sonic-boom overpressure from 1.3 to 1.0 pounds per square foot was achieved by varying the flight profile slightly from that for optimum performance

AN Ultrasonic Ray-Trance Code for Complex Geometry Applications

Many applications of ultrasonic testing (UT) are made difficult by the complex geometrical shape of the part to be inspected. A simple ray-trace analysis of the geometry may suffice to determine transducer positions and beam angles to provide adequate coverage of the region to be interrogated. In addition, however, the analyst must have estimates of backscattered amplitudes to determine if flaw signals are measurable. Thus, a combination of complex-geometry ray tracing with calculations of flaw-scattering amplitudes is required for the design and optimization of UT procedures

Preliminary performance of a vertical-attitude takeoff and landing, supersonic cruise aircraft concept having thrust vectoring integrated into the flight control system

A performance study was made of a vertical attitude takeoff and landing (VATOL), supersonic cruise aircraft concept having thrust vectoring integrated into the flight control system. Those characteristics considered were aerodynamics, weight, balance, and performance. Preliminary results indicate that high levels of supersonic aerodynamic performance can be achieved. Further, with the assumption of an advanced (1985 technology readiness) low bypass ratio turbofan engine and advanced structures, excellent mission performance capability is indicated

Design of a mixer for the thrust-vectoring system on the high-alpha research vehicle

One of the advanced control concepts being investigated on the High-Alpha Research Vehicle (HARV) is multi-axis thrust vectoring using an experimental thrust-vectoring (TV) system consisting of three hydraulically actuated vanes per engine. A mixer is used to translate the pitch-, roll-, and yaw-TV commands into the appropriate TV-vane commands for distribution to the vane actuators. A computer-aided optimization process was developed to perform the inversion of the thrust-vectoring effectiveness data for use by the mixer in performing this command translation. Using this process a new mixer was designed for the HARV and evaluated in simulation and flight. An important element of the Mixer is the priority logic, which determines priority among the pitch-, roll-, and yaw-TV commands