Effect of Wing Modifications on the Longitudinal Stability of a Tailless All-wing Airplane Model

Effect of Wing Modifications on the Longitudinal Stability of a Tailless All-wing Airplane Model
Author: Charles L. Seacord
Publisher:
Total Pages: 30
Release: 1945
Genre: Aerodynamics
ISBN:

Summary: An investigation of the power-off longitudinal stability characteristics of a tailless all-wing airplane model with various wing modifications has been made in the Langley free-flight tunnel. Force and tuft tests were made on the model in the original condition, with the wing tips rotated for washout, with rectangular and swept-forward tips, and with various slat arrangements. Flight tests were made with the original wing and with the original wing equipped with the most promising modifications. The results indicated that changes in tip plan form or rotation of the wing tips did not appreciably reduce the instability at high lift coefficients. Addition of wing slats, however, improved the longitudinal stability at the stall when the slat extended far enough inboard to cover the area that tended to stall first.

A Piloted Simulator Investigation of Ground Effect on the Landing Maneuver of a Large, Tailless, Delta-wing Airplane

A Piloted Simulator Investigation of Ground Effect on the Landing Maneuver of a Large, Tailless, Delta-wing Airplane
Author: C. Thomas Snyder
Publisher:
Total Pages: 60
Release: 1970
Genre: Airplanes
ISBN:

The influence of ground effect on the landing flare characteristics of a supersonic transport airplane (SST) was investigated in a fixed cockpit simulator. Simulations of an ogee-modified delta-wing F5D-1 airplane and a subsonic jet transport were used for evaluating the simulator and as a reference configurations during landing comparisons. Dynamic responses of the SST to seven different ground-effect models during controls-fixed and constant-attitude descents are also presented, followed by piloted subjective assessments. A summary of ground effects on delta-like wings is included in the appendixes.

WIG Craft and Ekranoplan

WIG Craft and Ekranoplan
Author: Liang Yun
Publisher: Springer Science & Business Media
Total Pages: 459
Release: 2009-12-03
Genre: Technology & Engineering
ISBN: 144190042X

In the last half-century, high-speed water transportation has developed rapidly. Novel high-performance marine vehicles, such as the air cushion vehicle (ACV), surface effect ship (SES), high-speed monohull craft (MHC), catamaran (CAT), hydrofoil craft (HYC), wave-piercing craft (WPC) and small water area twin hull craft (SWATH) have all developed as concepts, achieving varying degrees of commercial and military success. Prototype ACV and SES have achieved speeds of 100 knots in at calm con- tions; however, the normal cruising speed for commercial operations has remained around 35–50 knots. This is partly due to increased drag in an average coastal s- way where such craft operate services and partly due to limitations of the propulsion systems for such craft. Water jets and water propellers face limitations due to c- itation at high speed, for example. SWATH are designed for reduced motions in a seaway, but the hull form is not a low drag form suitable for high-speed operation. So that seems to lead to a problem – maintain water contact and either water propulsion systems run out of power or craft motions and speed loss are a problem in higher seastates. The only way to higher speed would appear to be to disconnect completely from the water surface. You, the reader, might respond with a question about racing hydroplanes, which manage speeds of above 200 kph. Yes, true, but the power-to-weight ratio is extremely high on such racing machines and not economic if translated into a useful commercial vessel.