Engineering topics

Washburn, G. F.

Publications and source records attributed to Washburn, G. F..

8 records

NASA NTRS1981

Design and analysis of a fuel-efficient single-engine, turboprop-powered, business airplane

The speed, range, payload, and fuel efficiency of a general aviation airplane powered by one turboprop engine was determined and compared to a twin engine turboprop aircraft. An airplane configuration was developed which can carry six people for a noreserve range of 2,408 km at a cruise speed above 154 m/s, and a cruise altitude of about 9,144 m. The cruise speed is comparable to that of the fastest of the current twin turboprop powered airplanes. It is found that the airplane has a cruise specific range greater than all twin turboprop engine airplanes flying in its speed range and most twin piston engine airplanes flying at considerably slower cruise airspeeds.

Martin, G. L.↗

NASA NTRS1981

A study of high-altitude manned research aircraft employing strut-braced wings of high-aspect-ratio

The effect of increased wing aspect ratio of subsonic aircraft on configurations with and without strut bracing. Results indicate that an optimum cantilever configuration, with a wing aspect ratio of approximately 26, has a 19% improvement in cruise range when compared to a baseline concept with a wing aspect ratio of approximately 10. An optimum strut braced configuration, with a wing aspect ratio of approximately 28, has a 31% improvment in cruise range when compared to the same baseline concept. This improvement is mainly due to the estimated reduction in wing weight resulting from use of lifting struts. All configurations assume the same mission payload and fuel. The drag characteristics of the wings are enhanced with the use of laminar flow airfoils. A method for determining the extent of attainable natural laminar flow, and methods for preliminary structural design and for aerodynamic analysis of wings lifting struts are presented.

Smith, P. M.↗

NASA NTRS1980

Preliminary design characteristics of a subsonic business jet concept employing an aspect ratio 25 strut braced wing

The advantages of replacing the conventional wing on a transatlantic business jet with a larger, strut braced wing of aspect ratio 25 were evaluated. The lifting struts reduce both the induced drag and structural weight of the heavier, high aspect ratio wing. Compared to the conventional airplane, the strut braced wing design offers significantly higher lift to drag ratios achieved at higher lift coefficients and, consequently, a combination of lower speeds and higher altitudes. The strut braced wing airplane provides fuel savings with an attendant increase in construction costs.

Turriziani, R. V.↗

NASA NTRS1979

Boeing 747 aircraft with large external pod for transporting outsize cargo

The effect on structural arrangement, system weight, and range performance of the cargo pod payload carrying capability was determined to include either the bridge launcher or a spacelab module on a Boeing 747 aircraft. Modifications to the carrier aircraft and the installation time required to attach the external pod to the 747 were minimized. Results indicate that the increase in pod size was minimal, and that the basic 747 structure was adequate to safely absorb the load induced by ground or air operation while transporting either payload.

Price, J. E.↗

NASA NTRS1978

Preliminary design characteristics of a subsonic business jet concept employing laminar flow control

Aircraft configurations were developed with laminar flow control (LFC) and without LFC. The LFC configuration had approximately eleven percent less parasite drag and a seven percent increase in the maximum lift-to drag ratio. Although these aerodynamic advantages were partially offset by the additional weight of the LFC system, the LFC aircraft burned from six to eight percent less fuel for comparable missions. For the trans-atlantic design mission with the gross weight fixed, the LFC configuration would carry a greater payload for ten percent fuel per passenger mile.

Turriziani, R. V.↗

NASA NTRS1978

Boeing-747 aircraft with external cargo pod

An analysis was conducted to investigate the feasibility of mounting a detachable pod to the underside of the fuselage of a Boeing Model 747 aircraft to carry outsized cargo in case of military emergency. The analysis showed that the 747 configured with the pod and carrying only a bridge launcher as payload attained a range of 8.70 Mm (4 700 n. mi.) at Mach .68. This range was based on a maximum take-off gross weight of 3.447 MN (775 000 1bf) which included 212 kN (47 700 lbf) pod weight and 543 kN (122 000 lbf) payload (bridge launcher).

Quartero, C. B.↗

NASA NTRS1978

Design of a large span-distributed load flying-wing cargo airplane with laminar flow control

A design study was conducted to add laminar flow control to a previously design span-distributed load airplane while maintaining constant range and payload. With laminar flow control applied to 100 percent of the wing and vertical tail chords, the empty weight increased by 4.2 percent, the drag decreased by 27.4 percent, the required engine thrust decreased by 14.8 percent, and the fuel consumption decreased by 21.8 percent. When laminar flow control was applied to a lesser extent of the chord (approximately 80 percent), the empty weight increased by 3.4 percent, the drag decreased by 20.0 percent, the required engine thrust decreased by 13.0 percent, and the fuel consumption decreased by 16.2 percent. In both cases the required take-off gross weight of the aircraft was less than the original turbulent aircraft.

Lovell, W. A.↗

NASA NTRS1974

A study of subsonic transport aircraft configurations using hydrogen (H2) and methane (CH4) as fuel

The acceptability of alternate fuels for future commercial transport aircraft are discussed. Using both liquid hydrogen and methane, several aircraft configurations are developed and energy consumption, aircraft weights, range and payload are determined and compared to a conventional Boeing 747-100 aircraft. The results show that liquid hydrogen can be used to reduce aircraft energy consumption and that methane offers no advantage over JP or hydrogen fuel.

Snow, D. B.↗