Engineering topics

Rolls, L. S.

Publications and source records attributed to Rolls, L. S..

At least 19 records

NASA NTRS1977

Experimental investigations of thrust vectoring systems for VTOL aircraft

This paper presents a summary of two technology programs sponsored by NASA to investigate the characteristics of two thrust vectoring schemes for V/STOL aircraft. The operational capability of the VTOL aircraft is dependent on maximum utilization of the installed thrust in both the cruise and powered lift modes of flight. An effective thrust vectoring system on the cruise propulsion unit is therefore essential to provide maximum payload in hover and STOL plus minimum specific fuel consumption in loiter and cruise. Introducing a high by-pass ratio fan system, augmenting the gas generator thrust, as the propulsion system for VTOL aircraft places increased significance on the performance of the relatively short coupled thrust vectoring systems. The two programs discussed herein include both large-scale and small-scale tests of a vectoring hood system with a vented, internal-lip and swivel nozzle systems. These tests indicated that a satisfactory thrust vectoring system can be developed.

Rolls, L. S.↗

NASA NTRS1976

Review of V/STOL lift/cruise fan technology

This paper presents an overview of supporting technology programs conducted to reduce the risk in the joint NASA/Navy Lift/Cruise Fan Research and Technology Aircraft Program. The aeronautical community has endeavored to combine the low-speed and lifting capabilities of the helicopter with the high-speed capabilities of the jet aircraft; recent developments have indicated a lift/cruise fan propulsion system may provide these desired characteristics. NASA and the Navy have formulated a program that will provide a research and technology aircraft to furnish viability of the lift/cruise fan aircraft through flight experiences and obtain data on designs for future naval and civil V/STOL aircraft. The supporting technology programs discussed include: (1) design studies for operational aircraft, a research and technology aircraft, and associated propulsion systems; (2) wind-tunnel tests of several configurations; (3) propulsion-system thrust vectoring tests; and (4) simulation. These supporting technology programs have indicated that a satisfactory research and technology aircraft program can be accomplished within the current level of technology.

Rolls, L. S.↗

NASA NTRS1976

Wind tunnel investigation of a large-scale model of a lift/cruise fan V/STOL aircraft

An investigation was conducted in the Ames 40- by 80-Foot wind tunnel to determine the aerodynamic characteristics of a large scale model of a lift/cruise fan V/STOL aircraft. The model was equipped with three fans, one mounted in the forward section of the fuselage in a lift mode, and two mounted on top of the wing adjacent to the fuselage in a lift/cruise mode. The data that were obtained include longitudinal and lateral-directional characteristics of the model, with the horizontal tail on and off, for both the Powered lift and cruise configurations. Powered lift data were obtained at several wind tunnel velocities and at several lift/cruise fan thrust vector angles by varying the position of the hooded deflectors from 0 deg. (the cruise condition) to 90 deg.

Gambucci, B. J.↗

NASA NTRS1974

Integrated propulsion/energy transfer control systems for lift-fan V/STOL aircraft

An integrated propulsion/control system for lift-fan transport aircraft is described. System behavior from full-scale experimental and piloted simulator investigations are reported. The lift-fan transport is a promising concept for short-to-medium haul civil transportation and for other missions. The lift-fan transport concept features high cruise airspeed, favorable ride qualities, small perceived noise footprints, high utilization, transportation system flexibility, and adaptability to VTOL, V/STOL, or STOL configurations. The lift-fan transport has high direct operating costs in comparison to conventional aircraft, primarily because of propulsion system and aircraft low-speed control system installation requirements. An integrated lift-fan propulsion system/aircraft low-speed control system that reduces total propulsion system and control system installation requirements is discussed.

Deckert, W. H.↗

NASA NTRS1969