Twenty-five years of aerodynamic research with IR imaging: A survey

Infrared imaging used in aerodynamic research evolved during the last 25 years into a rewarding experimental technique for investigation of body-flow viscous interactions, such as heat flux determination and boundary layer transition. The technique of infrared imaging matched well its capability to produce useful results, with the expansion of testing conditions in the entire spectrum of wind tunnels, from hypersonic high-enthalpy facilities to cryogenic transonic wind tunnels. With unique achievements credited to its past, the current trend suggests a change in attitude towards this technique: from the perception as an exotic, project-oriented tool, to the status of a routine experimental procedure

Model Scale Investigation of Blade Root Cavitation Erosion on a Set of Marine Propellers

The present study is focused on the experimental analysis of the erosion caused by cavitation occurring at the blade root for a set of three model scale marine propellers. The experimental method is based on the adoption of soft paint technique together with cavitation observations. Cavitation dynamics and erosion damage patterns are recorded using three standard cameras and one high speed camera. Standard cameras are fixed on the top of test section to continuously monitor the effect of erosion damage on the blade root, the high-speed camera has been placed at different positions to investigate detailed evolution and collapse of bubbles on pressure and suction side of propeller blades. The soft paint test damage patterns have been simultaneously analysed with the high- speed videos, and results showed remarkable agreement between the occurrence of damage on the blades and the bubble collapse of cavitation. The damage pattern and cavities collapse seem to be inversely related with the inception time of damage

Robots Refurbish Space Shuttle Hardware USBI

USBI, a division of United Technologies Corporation (UTC ), was awarded a contract by the National Aeronautics and Space Administration (NASA) to refurbish the non-motor sections (nosecap, frustum, forward skirt, and aft skirt) of the Solid Rocket Boosters (SRB) used in the space shuttle program. As NASA\u27s major contractor for processing and refurbishment of the SRB\u27s, our company has successfully refurbished all the SRB\u27s flight hardware to date. The planned insulation refurbishment process of the SRB\u27s consists of thermal protection system (TPS) removal; surface preparation; reapplication of Marshall Sprayable Ablative (MSA-2), a thermal ablative material developed at Marshall Space Flight Center; and topcoat spraying of Hypalon paint to seal the ablative material. In the past, refurbishment of the SRB\u27s was done by hand at the Vehicle Assembly Building (VAB). This process was slow and tedious, and introduced personnel to potentially hazardous working environments. A means of reducing costs and providing enhanced quality assurance was desired. Therefore, the need arose to implement a degree of automation to the refurbishment process. The introduction of a new automated process system would reduce the manual labor element, limiting the need for personnel to come in direct contact with hazardous materials. And because of the reliability and accuracy of robotics, NASA would be assured of receiving the highest possible quality product , at the lowest cost

New devices for flow measurements: Hot film and burial wire sensors, infrared imagery, liquid crystal, and piezo-electric model

An experimental program aimed at identifying areas in low speed aerodynamic research where infrared imaging systems can make significant contributions is discussed. Implementing a new technique, a long electrically heated wire was placed across a laminar flow. By measuring the temperature distribution along the wire with the IR imaging camera, the flow behavior was identified

Multimedia Technologies and Virtual Organizing of Learning

This paper addresses the issue of what are the efficient uses of multimedia technologies in teaching processes, and what are the conditions that require these technologies in online learning. The background of this paper is made by exploring online master programs, given the burgeoning interest of this emerging phenomenon of the future of distance learning. Rigorous analysis and careful measurement of communication required were covered by empirical data. This analysis is to provide an early window into several communications processes and tasks that occur in virtual context of learning, using multimedia technologies.multimedia technologies, virtual organization, online learning, communication, effectiveness of learning

Shock control of a low-sweep transonic laminar flow wing

This paper presents a combined experimental and computational study of a low-sweep transonic natural laminar flow (NLF) wing with shock-control bumps (SCBs). A transonic NLF wing with a relatively low sweep angle of 20 deg was chosen for this study. To avoid the complexity of the flow introduced by perforated/slotted walls commonly used for transonic wind-tunnel tests for reducing the wall interference, both experimental tests and computational simulations were conducted with solid wind-tunnel wall conditions. This allows for like-to-like validation of the computational simulation. Optimization of the shock-control bumps was first conducted to design the wind-tunnel test model with bumps. Two critical parameters of the three-dimensional SCBs for shock control (i.e., bump crest position and bump height) were optimized in terms of total drag reduction at the given design point in the wind tunnel. We show that the strong shock wave on the low-sweep NLF wing can be effective controlled by well-designed SCBs deployed along the wing span. The optimized SCBs result in 18.5% pressure drag reduction with 5% viscous drag penalty, and the SCBs also bring some benefits at off-design conditions. The wind-tunnel tests include pressure measurement, particle image velocimetry, and temperature-sensitive paint to provide detailed insight into the shock-control flowfield and to validate the computational simulations. Comparisons include surface pressure profile, velocity distribution, and transition location

Index to NASA Tech Briefs, 1975

This index contains abstracts and four indexes--subject, personal author, originating Center, and Tech Brief number--for 1975 Tech Briefs

Suited for spacewalking: A teacher's guide with activities

This publication is an activity guide for teachers on spacesuits and spacewalking. It uses the intensive interest many children have in space exploration as a launching point for hands-on-opportunities. The guide begins with brief discussions of the space environment, the history of space walking, the Space Shuttle spacesuit, and working in space. These are followed by a series of activities that enable children to explore the space environment as well as the science and technology behind the functions of spacesuits. The activities are not rated for specific grade levels because they can be adapted for students of many ages. The guide concludes with a brief glossary as well as references and resources