Influence of a walking mechanism on the hydrodynamic performance of a high-speed wheeled amphibious vehicle

In order to reduce the resistance and increase speed for a high-speed wheeled amphibious vehicle, a wheel-retracting mechanism was applied to a walking mechanism and the influence was researched. Firstly, to obtain a reliable numerical method, a realizable shear stress transport (SST) k-ω turbulence model and computational fluid dynamic (CFD) model built by an overset mesh technique was used and compared with the corresponding model tests. Secondly, the effect of the wheels' flip angle on resistance, heave and pitch was investigated. Then, the wheel well was optimized by numerical simulation. Finally, the results showed that the influence of the wheels on resistance was more significant, and the larger the wheels' flip angle was, the more significant the resistance reduction would be. An optimized wheel well was beneficial to resistance reduction. Furthermore, the running attitude became steadier, thereby decreasing the heave and pitch.</p

Aeronautical enginnering: A cumulative index to a continuing bibliography (supplement 312)

This is a cumulative index to the abstracts contained in NASA SP-7037 (301) through NASA SP-7073 (311) of Aeronautical Engineering: A Continuing Bibliography. NASA SP-7037 and its supplements have been compiled by the Center for AeroSpace Information of the National Aeronautics and Space Administration (NASA). This cumulative index includes subject, personal author, corporate source, foreign technology, contract number, report number, and accession number indexes

Proceedings of the Interagency Workshop on Lighter than Air Vehicles

Papers presented at the workshop are reported. Topics discussed include: economic and market analysis, technical and design considerations, manufacturing and operations, design concepts, airship applications, and unmanned and tethered systems

Influence on Stern Flaps in Resistance Performance of a Caterpillar Track Amphibious Vehicle

In order to reduce the resistance and increasing speed for a caterpillar track amphibious vehicle (CTAV), the stern flaps were applied and the influence was researched. Numerical simulations performed by STAR-CCM&#x002B; and model towing test reveal that stern flaps have greatly reduced the resistance, trim, and sinkage of the CTAV when the length Froude number is between 0.63 and 1.05. The length and flap angle were optimized by numerical simulation. In addition, the residual resistance plays a dominant role in resistance reduction, which contributes to more than 90&#x0025; of the total resistance reduction. Installing stern flaps increase the vehicle waterline by 7&#x0025; and enhance the virtual-length effect. Furthermore, the running attitude becomes steadier, thereby decreasing the trim and sinkage. Therefore the resistance performance of the CTAV can be enhanced by installing stern flaps with a proper length at an optimal flap angle

A History of Materials and Technologies Development

The purpose of the book is to provide the students with the text that presents an introductory knowledge about the development of materials and technologies and includes the most commonly available information on human development. The idea of the publication has been generated referring to the materials taken from the organic and non-organic evolution of nature. The suggested texts might be found a purposeful tool for the University students proceeding with studying engineering due to the fact that all subjects in this particular field more or less have to cover the history and development of the studied object. It is expected that studying different materials and technologies will help the students with a better understanding of driving forces, positive and negative consequences of technological development, etc

Seventy years of life in the Victorian era embracing a travelling record in Australia, New Zealand and America, &c. / by a Physician.

Scanned from the original held in Rare Books & Special Collections, Barr Smith Library

Comparison of the vocabularies of the Gregg shorthand dictionary and Horn-Peterson's basic vocabulary of business letters

This study is a comparative analysis of the vocabularies of Horn and Peterson's The Basic Vocabulary of Business Letters1 and the Gregg Shorthand Dictionary.2 Both books purport to present a list of words most frequently encountered by stenographers and students of shorthand. The, Basic Vocabulary of Business Letters, published "in answer to repeated requests for data on the words appearing most frequently in business letters,"3 is a frequency list specific to business writing. Although the book carries the copyright date of 1943, the vocabulary was compiled much earlier. The listings constitute a part of the data used in the preparation of the 10,000 words making up the ranked frequency list compiled by Ernest Horn and staff and published in 1926 under the title of A Basic Writing Vocabulary: 10,000 Words Lost Commonly Used in Writing. The introduction to that publication gives credit to Miss Cora Crowder for the contribution of her Master's study at the University of Minnesota concerning words found in business writing. With additional data from supplementary sources, the complete listing represents twenty-six classes of business, as follows 1. Miscellaneous 2. Florists 3. Automobile manufacturers and sales companie

Space for mankind's benefit

Proceedings of conference on benefits of space exploration conducted at Huntsville, Alabama Nov. 197