MAY 1974

A74-10144 The technology and economics of commercial airplane design. I. J. E. Steiner (Boeing Co., Commercial Airplane Group, Renton, Wash.). Esso Air World, vol. 25, no. 5, 1973, p. 119-124.

Discussion of the relation between technology and economics in commercial aviation. Past and present priority orders of aircraft market requirements in speed, range, frequency, quietness, passenger comfort and economics are compared. Direct operating cost trends, aerodynamic efficiency trends, thrust-to-weight growth, engine fuel efficiency trends, payload efficiency, airline revenues vs passenger yield, progress in takeoff noise reduction, return on investment, and approach noise are covered. Improved technology, two-man crew, reduced block time and maintenance cost, and communality/ facilities compatibility are listed as elements of improved commercial aircraft design economics.

V.Z.

The energetic characteristics of the heating process are analyzed for the heating of the vaporized and condensed phases of substances within and outside the electrical field of an arc discharge. It is shown that the heating of substances by an arc discharge plasma has a potential as a technique for practical electric-to-thermal energy conversion. It is also found that the power delivered to the substance can be controlled within large limits by varying the electrical parameters of the arc and the thermophysical properties of the plasma arc gas when this electric-to-thermal energy conversion process is used. An efficiency in excess of 80% is indicated for this energy conversion method. V.Z.

A74-10691 # Physical behaviour of some biowaste gases in an ion engine. A. R. Martin (City University, London, England). American Institute of Aeronautics and Astronautics, Electric Propulsion Conference, 10th, Lake Tahoe, Nev., Oct. 31-Nov. 2, 1973,

Paper 73-1113. 7 p. 12 refs. Members, $1.50; nonmembers, $2.00. Research supported by the Science Research Council and Department of Trade and Industry.

The operation of a 100 mm diameter electron-bombardment ion engine using carbon dioxide, methane and nitrogen propellants was studied. The engine was of modern configurational design, but constructed to laboratory requirements rather than flight or engineering standards. The operation with nitrogen and methane was quite similar, and resulted in stable operation with reasonable efficiencies. Operation with carbon dioxide was anomalous, in that as utilization was increased a point occurred where the losses rose and the beam current fell. This was thought to be related to a change in the cathode work function as a result of oxygen poisioning. (Author)

A74-11020 #

Satellite solar power stations to meet future energy demands. P. E. Glaser (Arthur D. Little, Inc., Cambridge, Mass.). Industries Atomiques et Spatiales, vol. 17, July-Aug. 1973, p. 77-95. 16 refs. In English and French.

A satellite solar power system (SSPS) can be designed to generate electrical power on earth at specific levels ranging from about 3000 to 15,000 megawatt. Over this range of power output the orbiting portion of the SSPS exhibits the best power-to-weight characteristics. Additional solar collector arrays and antennas could be added to establish an SSPS system at a desired orbital location. With the receiving antenna placed either on land or on platforms over water near major load centers and tied into a power transmission grid, power could be delivered to almost any desired geographic location. F.R.L.

A74-11219 # Gas generators A perspective. W. H. Cutler (Lockheed Missiles and Space Co., Inc., Sunnyvale, Calif.). American Institute of Aeronautics and Astronautics and Society of Automotive Engineers, Propulsion Conference, 9th, Las Vegas, Nev., Nov. 5-7, 1973, AIAA Paper 73-1168. 7 p. Members, $1.50; nonmembers, $2.00.

The gas generator is usually thought of as a light weight, high power, short duration energy source, used mainly in aircraft and missiles. This premise is re-examined by viewing gas generators in the perspective of other energy sources with similar or overlapping characteristics and applications, to see where gas generators have a performance edge and where gaps exist which are opportunities for new gas generator applications. The alternative energy sources, which in addition to gas generators include gas turbines, reciprocating engines, compressed gas containers and hydraulic accumulators, flywheels, batteries, fuel cells, and solar photovoltaic cells, are 'first described in terms of their energy conversion process and the form in which their output energy is delivered. They are then compared on the basis of stored energy density and applicable power levels. Next, the factors involved in matching an energy source to its operating environment are enumerated. Finally, a number of new applications for gas generators are suggested which introduce new requirements in both technical and marketing areas. (Author)

A74-11257 # Solid state hydrogen gas generator. W. H. Barber, W. F. Beckert, and O. H. Dengel (U.S. Navy, Naval Ordnance Station, Indian Head, Md.). American Institute of Aeronautics and

Astronautics and Society of Automotive Engineers, Propulsion Conference, 9th, Las Vegas, Nev., Nov. 5-7, 1973, AIAA Paper 73-1232. 4 p. Members, $1.50; nonmembers, $2.00.

A family of light-weight solid state hydrogen gas generators has been developed for inflation of rocket deployed balloon structures. The generators utilize a reaction between metal, hydrides and ammonium halides. The chemical reaction is thermally initiated. The generators tested so far are capable of inflating 1-15 cu. ft. structures at STP. The development of solid state hydrogen gas generators for inflation of 1,000-100,000 cu. ft. balloon structures appears feasible. (Author)

A74-11315 # The case for hydrogen fueled transport aircraft. G. D. Brewer (Lockheed-California Co., Burbank, Calif.). American Institute of Aeronautics and Astronautics and Society of Automotive Engineers, Propulsion Conference, 9th, Las Vegas, Nev., Nov. 5-7, 1973, AIAA Paper 73-1323. 13 p. 14 refs. Members, $1.50; nonmembers, $2.00.

Arguments in favor of the substitution of liquid hydrogen for oil to power commercial aircraft are presented. Shortage of petroleum in the United States and the need for import will lead to unacceptable dependence on foreign nations, will cost the U.S. heavily in terms of deficit balance of payments, and can become a continuous threat of interruption of oil supply that will endanger our independence in the fields of commerce, world trade, diplomacy, and even our national security. In addition, hydrogen offers potential advantages when used in aircraft. Examples of subsonic and supersonic commercial aircraft are examined to determine the advantages in performance, pollution, noise, and cost. Some problems associated with the use of liquid hydrogen as a fuel are discussed. V.P.

A74-12201

Spacecraft electrical power. E. Stofel (Hughes Aircraft Co., El Segundo, Calif.). In: EASCON '73; Electronics and Aerospace Systems Convention, Washington, D.C., September 17-19, 1973, Record. New York, Institute of Electrical

and Electronics Engineers, Inc., 1973, p. 225-231. 13 refs.

Present developments in spacecraft power systems are placing strong emphasis on component weight reduction and efficiency improvements as a means of obtaining spacecraft with more power. The most striking of these are: (1) the improved efficiency of solar cells; (2) light-weight, large area solar arrays; (3) the possibility of light-weight nickel-hydrogen energy storage units; and (4) restructuring of power control electronics at higher operating voltages. These developments will tend to encourage further use of solar cell power systems for increasingly larger spacecraft, a trend that is already well established by the use of solar cells on almost all past and present spacecraft. Nuclear powered systems are advancing at a slower rate, with limited funding, and, therefore, apparently will remain relegated to special situations, such as missions to the outer planets or where physical compactness is a distinctive requirement. (Author)

A74-12242* # High voltage solar cell power generating system for regulated solar array development. E. Levy, Jr. (Hughes Aircraft Co., Los Angeles, Calif.) and A. C. Hoffman (NASA, Lewis Research Center, Cleveland, Ohio). American Institute of Aeronautics and Astronautics, Electric Propulsion Conference, 10th, Lake Tahoe, Nev., Oct 31-Nov. 2, 1973, Paper 73-1105. 13 p. Members, $1.50; nonmembers, $2.00. Contract No. NAS3-15826.

A laboratory solar power system regulated by on-panel switches has been delivered for operating high power (3 kw), high voltage (15,000 volt) loads (communication tubes, ion thrusters). The modular system consists of 26 solar arrays, each with an integral light source and cooling system. A typical array contains 2560 seriesconnected cells. Each light source consists of twenty 500 watt tungsten iodide lamps providing plus or minus 5 per cent uniformity at one solar constant. An array temperature of less than 40 C is achieved using an infrared filter, a water cooled plate, a vacuum hold-down system, and air flushing.

(Author)

A74-12794 #

Actual state of French technical developments concerning sources of space power (Etat actuel des développements techniques français en matière de sources de puissance spatiales). W. Palz and C. Martin (Centre National d'Etudes Spatiales, Paris, France). International Astronautical Federation, International Astronautical Congress, 24th, Baku, Azerbaidzhan SSR, Oct. 7-13, 1973, ** Paper. 17 p. 6 refs. In French.

French progress in study and research concerning solar genera tors for space applications is described. On the level of components = continuing effort is being put forth to perfect silicon cells. The development of thin-film cadmium sulfide cells has reached the stage of practicality. In the years to come complete commercial produc tion is expected. Rigid and flexible structures of solar panels have been developed in the 100 W to 10 kW range. Research and development work in this field is reviewed. F.R.L.

A74-12905 * #

Industrial use of aerospace technology. J. E. Burnett (NASA, Lewis Research Center, Cleveland, Ohio). International Astronautical Federation, International Astronautical Congress, 24th, Baku, Azerbaidzhan SSR, Oct. 7-13, 1973, Paper. 5 p.

Using a few selected examples of the several hundred successful transfers of aerospace technology to applications outside the aerospace field, it is shown that aerospace-related new technology does have many valuable nonaerospace uses. The examples presented include technology transfers to the machine tool and petroleum industries as well as to the fields of electric utilities and computeraided structure design. M.V.E.

A74-13234 * # Satellite nuclear power station: An engineering analysis. J. R. Williams, J. D. Clement (Georgia Institute of Technology, Atlanta, Ga.), R. J. Rosa, K. D. Kirby, and Y. Y. Yang. Research supported by NASA; Grant No. NGR-11-002-145. Atlanta, Ga., J.R. Williams, Georgia Institute of Technology, 1973. 143 p. 41 refs.

A nuclear-MHD power plant system which uses a compact non-breeder reactor to produce power in the multimegawatt range is analyzed. It is shown that, operated in synchronous orbit, the plant would transmit power safely to the ground by a microwave beam. Fuel reprocessing would take place in space, and no radioactive material would be returned to earth. Even the effect of a disastrous accident would have negligible effect on earth. A hydrogen moderated gas core reactor, or a colloid-core, or NERVA type reactor could also be used. The system is shown to approach closely the ideal of economical power without pollution. V.P.

A74-13293 #

Conversion of fuel nitrogen to NOx in a compact combustor. H. R. Hazard (Battelle Columbus Laboratories, Columbus, Ohio). American Society of Mechanical Engineers, Winter Annual Meeting, Detroit, Mich., Nov. 11-15, 1973, Paper 73WA/GT-2. 4 p. Members, $1.00; nonmembers, $3.00.

A low-nitrogen fuel, ASTM Jet A aviation kerosene, was doped with increasing amounts of pyridine as a means of increasing the content of chemically bound nitrogen; it was then burned at a rate of 50 lb/hr in a compact combustor incorporating staged air admission with a rich primary zone and water cooling of the walls. Each increase in fuel nitrogen content resulted in a significant increase in NOX in the combustion products, and it is estimated that as much as 90% of the fuel nitrogen was converted to NOx at very low nitrogen levels, decreasing to 55% conversion at higher levels. These results are consistent with data reported for large steam boilers and for small residential boilers. It appears that emission standards requiring very low levels of NOx emission will require use of fuels with very low nitrogen content. (Author)