Development of the technology for the fabrication of reliable laminar from control panels

Materials were assessed and fabrication techniques were developed for use in the manufacture of wing surface materials compatible with the application of both aluminum alloys and nonmetallic composites. The concepts investigated included perforations and slots in the metallic test panels and microporosity and perforations in the composite test panels. Perforations were produced in the metallic test panels by the electron beam process and slots were developed by controlled gaps between the metal sheets. Microporosity was produced in the composite test panels by the resin bleed process, and perforations were produced by the fugitive fiber technique. Each of these concepts was fabricated into test panels, and air flow tests were conducted on the panels

Study of the application of advanced technologies to laminar flow control systems for subsonic transports. Volume 1: Summary

A study was conducted to evaluate the technical and economic feasibility of applying laminar flow control to the wings and empennage of long-range subsonic transport aircraft compatible with initial operation in 1985. For a design mission range of 10,186 km (5500 n mi), advanced technology laminar-flow-control (LFC) and turbulent-flow (TF) aircraft were developed for both 200 and 400-passenger payloads, and compared on the basis of production costs, direct operating costs, and fuel efficiency. Parametric analyses were conducted to establish the optimum geometry for LFC and TF aircraft, advanced LFC system concepts and arrangements were evaluated, and configuration variations maximizing the effectiveness of LFC were developed. For the final LFC aircraft, analyses were conducted to define maintenance costs and procedures, manufacturing costs and procedures, and operational considerations peculiar to LFC aircraft. Compared to the corresponding advanced technology TF transports, the 200- and 400-passenger LFC aircraft realized reductions in fuel consumption up to 28.2%, reductions in direct operating costs up to 8.4%, and improvements in fuel efficiency, in ssm/lb of fuel, up to 39.4%. Compared to current commercial transports at the design range, the LFC study aircraft demonstrate improvements in fuel efficiency up to 131%. Research and technology requirements requisite to the development of LFC transport aircraft were identified

Study of the application of advanced technologies to laminar-flow control systems for subsonic transports. Volume 2: Analyses

For abstract, see N76-24144

Evaluation of advanced lift concepts and fuel conservative short-haul aircraft, volume 2

For abstract, see N75-20291

Evaluation of advanced lift concepts and fuel conservative short-haul aircraft, volume 1

The performance and economics of a twin-engine augmentor wing airplane were evaluated in two phases. Design aspects of the over-the-wing/internally blown flap hybrid, augmentor wing, and mechanical flap aircraft were investigated for 910 m. field length with parametric extension to other field lengths. Fuel savings achievable by application of advanced lift concepts to short-haul aircraft were evaluated and the effect of different field lengths, cruise requirements, and noise levels on fuel consumption and airplane economics at higher fuel prices were determined. Conclusions and recommendations are presented

Surface water–groundwater interactions along the Blanco River of central Texas, USA

The Blanco River is a very important resource for water supplies in the Hill Country of central Texas. Some communities and properties along the river use the surface water directly. But, the Blanco River is more significant in the role it plays in providing recharge to the karstic Trinity and Edwards Aquifers. Recent studies have given a better indication of the complexity of the interactions between surface water and groundwater in the area. Besides being a water supply to a population of several hundred thousand people, water originally flowing in the Blanco River provides flow to springs that host a number of endangered species. The Blanco River is characterized by alternating gaining and losing stretches due to the presence of springs that discharge water into the river and swallets that drain water from the river. Trinity units outcrop in the western part of the study area, and Edwards units outcrop in the eastern part of the study area. Normal faulting along the Balcones Fault Zone has juxtaposed the older, stratigraphically underlying Trinity units against the Edwards units to the east. The region consists primarily of Lower Cretaceous limestone, dolomite, and marl. One of the more significant springs along the Blanco River is Pleasant Valley Spring. During below-average flow conditions, Pleasant Valley Spring becomes the headwaters of the Blanco River even though the headwaters, under wet conditions, are about 50 km upstream. These studies, summarized in this paper, provide a greater understanding of the surface water and groundwater resources in the area which will help guide policies for groundwater management and preservation of springflows and groundwater supplies