Hypersonic cruise aircraft propulsion integration study, volume 1

A hypersonic cruise transport conceptual design is described. The integration of the subsonic, supersonic, and hypersonic propulsion systems with the aerodynamic design of the airframe is emphasized. An evaluation of various configurations of aircraft and propulsion integration concepts, and selection and refinement of a final design are given. This configuration was used as a baseline to compare two propulsion concepts - one using a fixed geometry dual combustion mode scramjet and the other a variable geometry ramjet engine. Both concepts used turbojet engines for takeoff, landing and acceleration to supersonic speed

Minimum energy, liquid hydrogen supersonic cruise vehicle study

The potential was examined of hydrogen-fueled supersonic vehicles designed for cruise at Mach 2.7 and at Mach 2.2. The aerodynamic, weight, and propulsion characteristics of a previously established design of a LH2 fueled, Mach 2.7 supersonic cruise vehicle (SCV) were critically reviewed and updated. The design of a Mach 2.2 SCV was established on a corresponding basis. These baseline designs were then studied to determine the potential of minimizing energy expenditure in performing their design mission, and to explore the effect of fuel price and noise restriction on their design and operating performance. The baseline designs of LH2 fueled aircraft were than compared with equivalent designs of jet A (conventional hydrocarbon) fueled SCV's. Use of liquid hydrogen for fuel for the subject aircraft provides significant advantages in performance, cost, noise, pollution, sonic boom, and energy utilization

Study of active cooling for supersonic transports

The potential benefits of using the fuel heat sink of hydrogen fueled supersonic transports for cooling large portions of the aircraft wing and fuselage are examined. The heat transfer would be accomplished by using an intermediate fluid such as an ethylene glycol-water solution. Some of the advantages of the system are: (1) reduced costs by using aluminum in place of titanium, (2) reduced cabin heat loads, and (3) more favorable environmental conditions for the aircraft systems. A liquid hydrogen fueled, Mach 2.7 supersonic transport aircraft design was used for the reference uncooled vehicle. The cooled aircraft designs were analyzed to determine their heat sink capability, the extent and location of feasible cooled surfaces, and the coolant passage size and spacing

Study of LH2 fueled subsonic passenger transport aircraft

The potential of using liquid hydrogen as fuel in subsonic transport aircraft was investigated to explore an expanded matrix of passenger aircraft sizes. Aircraft capable of carrying 130 passengers 2,780 km (1500 n.mi.); 200 passengers 5,560 km (3000 n.mi.); and 400 passengers on a 9,265 km (5000 n.mi.) radius mission, were designed parametrically. Both liquid hydrogen and conventionally fueled versions were generated for each payload/range in order that comparisons could be made. Aircraft in each mission category were compared on the basis of weight, size, cost, energy utilization, and noise

Ion engine thrust vector study, phase 2 Quarterly report

Performance prediction for expected thrust misalignment in electron bombardment ion thruste

The political dimension of seasonal allocations: Developing a seasonal allocation strategy in a water-short system in Sri Lanka

Water allocation, Irrigation programs, Reservoirs, Participatory management, Farmer participation, Water rights, Irrigated farming, Rice, Water shortage, Farmers' attitudes, Farmer-agency interactions, Sri Lanka

Ion engine thrust vector study

Probability of thrust vector misalignment in ion thrustor arra

Intellectual Capital and the Birth of U.S. Biotechnology Enterprises

We examine the relationship between the intellectual capital of scientists making frontier discoveries, the presence of great university bioscience programs, the presence of venture capital firms, other economic variables, and the founding of U.S. biotechnology enterprises during 1976-1989. Using a linked cross-section/time- series panel data set, we find that the timing and location of the birth of biotech enterprises is determined primarily by intellectual capital measures, particularly the local number of highly productive 'star' scientists actively publishing genetic sequence discoveries. Great universities are likely to grow and recruit star scientists, but their effect is separable from the universities. When the intellectual capital measures are included in our poisson regressions, the number of venture capital firms in an area reduces the probability of foundings. At least early in the process, star scientists appear to be the scarce, immobile factors of production. Our focus on intellectual capital is related to knowledge spillovers, but in this case 'natural excludability' permits capture of supranormal returns by scientists. Given this reward structure technology transfer was vigorous without any special intermediating structures. We believe biotechnology may be prototypical of the birth patterns in other innovative industries.

Assessment of crash fire hazard of LH sub 2 fueled aircraft

The relative safety of passengers in LH2 - fueled aircraft, as well as the safety of people in areas surrounding a crash scene, has been evaluated in an analytical study. Four representative circumstances were postulated involving a transport aircraft in which varying degrees of severity of damage were sustained. Potential hazard to the passengers and to the surroundings posed by the spilled fuel was evaluated for each circumstance. Corresponding aircraft fueled with liquid methane, Jet A, and JP-4 were also studied in order to make comparisons of the relative safety. The four scenarios which were used to provide a basis for the evaluation included: (1) a small fuel leak internal to the aircraft, (2) a survivable crash in which a significant quantity of fuel is spilled in a radial pattern as a result of impact with a stationary object while taxiing at fairly low speed, (3) a survivable crash in which a significant quantity of fuel is spilled in an axial pattern as a result of impact during landing, and (4) a non-survivable crash in which a massive fuel spill occurs instantaneously

Ion rocket engine development summary report

Design, fabrication, life testing, and supporting research of cesium contact ion rocket engin