Engineering topics
Publications and source records attributed to Weber, R. J..
A supersonic combustion rocket is provided in which a small rocket motor is substituted for heavy turbo pumps in a conventional rocket engine. The substitution results in a substantial reduction in rocket engine weight. The flame emanating from the small rocket motor can act to ignite non-hypergolic fuels.
Estimates of the prospects for quiet airplanes in the future are summarized. The SST using afterburning turbojets and no sound suppression is estimated to produce 129 EPNdb on the sideline. Suppression devices and operating techniques can reduce this noise markedly. The present fleet of 707's and DC-8's produces noises nearly as high as 120 decibels on approach. Combinations of sound absorbing devices and engine modifications are expected to give a noise near 100 decibels. The new advanced technology transports (ATT) are being studied with two noise goals in mind: one is 10 decibels and the other is 20 decibels below the FAR level of 106 on takeoff. New trijets using new quiet engines are expected to meet 90 EPNdb. Future advances in technology are expected to yield another 5 decibels to give noise levels of 80 EPNdb. The STOL airplane has a noise goal of 95 EPNdb along a sideline 500 feet from the runway.
The higher heating value of hydrogen relative to JP fuel is estimated to reduce fuel weight by three fold and gross weight by 40 percent for comparable designed airplanes of equal payload and range. Engine design parameters were varied to determine the influence of lower noise goals on gross weight and direct operating cost. At current fuel prices, the DOC of a hydrogen airplane would be much higher than that of a JP airplane. A methane airplane could offer an 8.5-percent lower KOC than JP. But future shortages may escalate the prices of both JP and methane, whereas the price of hydrogen manufactured hydrolytically could be reduced from present levels. If in the future all three fuels are postulated to have equal costs per unit of energy, the DOC for hydrogen could be as much as 20 percent below that for JP on the reference 4000-nautical-mile mission. Longer ranges or lower noise requirements would improve the advantage of hydrogen.
A concept is presented that combines the low-noise and high-thrust characteristics of a turbofan at takeoff, together with its high efficiency at subsonic flight speeds, with the high efficiency of a turbojet at supersonic cruise. It consists of a free turbine with tip fan mounted behind the turbine of a conventional turbojet engine. Fan air is supplied from blow-in doors or is ducted from the main engine inlet. At high flight speeds where fan augmentation is not desirable, the fan inlet is closed and the free turbine is stopped by adjustment of its variable-camber stators. Estimates of noise, cycle performance, and example configurations are presented for a typical supersonic transport application.
Cycle efficiency of air cooled steam power plants
Liquid methane as fuel for supersonic commercial air transport
Fuel tank pressurization and supercooling of liquid methane to minimize fuel boiloff problems in supersonic aircraft
Mission planning requirements for interplanetary space flights
Comparative data on liquid methane fuel and kerosene for supersonic transports
Liquified natural gas application to SST, noting improvement in engine performance with use of methane
Liquid natural gas as supersonic jet aircraft fuel
Liquid methane as fuel for SST propulsion in terms of cost, combustion heat and cooling capacity
Liquid methane fueled propulsion system for SST APPLICATION, noting increased payload capacity, propellant characteristics and design criteria for storage within aircraft
Turboramjet propulsion for efficient long range hypersonic transport aircraft
Propulsion for hypersonic transport aircraft
Fuel tank pressure-relief device for venting cryogenic liquid vapors through tubes with porous plug