A Validation Study of the Mixed-Foil Concept for High-Speed Hydrofoils

1976 ◽  
Vol 20 (02) ◽  
pp. 85-94
Author(s):  
D. P. Wang ◽  
Young T. Shen

A hydrodynamic validation study of the concept of the mixed foil has been conducted. A mixed foil is a streamlined hydrofoil equipped with a flap or other device which, above a certain speed, can be activated so as to change the flow around the foil into a supercavitating flow. At take-off and at moderate speeds, a mixed foil is operated as a subcavitating foil; at high speeds, it is operated as a supercavitating foil. During high-speed operations, a reduction in the wetted planform area of a mixed foil is proposed. The present study produces a design outline for the mixed foil and identifies essential problems which should be studied in the future. The analysis is illustrated by using hydrofoils with plano-convex sections. The lift-to-drag ratios at takeoff and at 45-knot and 83-knot cruising speeds are obtained.

TAPPI Journal ◽  
2009 ◽  
Vol 8 (1) ◽  
pp. 20-26 ◽  
Author(s):  
PEEYUSH TRIPATHI ◽  
MARGARET JOYCE ◽  
PAUL D. FLEMING ◽  
MASAHIRO SUGIHARA

Using an experimental design approach, researchers altered process parameters and material prop-erties to stabilize the curtain of a pilot curtain coater at high speeds. Part I of this paper identifies the four significant variables that influence curtain stability. The boundary layer air removal system was critical to the stability of the curtain and base sheet roughness was found to be very important. A shear thinning coating rheology and higher curtain heights improved the curtain stability at high speeds. The sizing of the base sheet affected coverage and cur-tain stability because of its effect on base sheet wettability. The role of surfactant was inconclusive. Part II of this paper will report on further optimization of curtain stability with these four variables using a D-optimal partial-facto-rial design.


Alloy Digest ◽  
1980 ◽  
Vol 29 (8) ◽  

Abstract RED CUT COBALT steel is made by adding 5% cobalt to the conventional 18% tungsten -4% chromium-1% vanadium high-speed steel. Cobalt increases hot or red hardness and thus enables the tool to maintain a higher hardness at elevated temperatures. This steel is best adapted for hogging cuts or where the temperature of the cutting point of the tool in increased greatly. It is well adapted for tools to be used for reaming cast-iron engine cylinders, turning alloy steel or cast iron and cutting nonferrous alloys at high speeds. This datasheet provides information on composition, physical properties, and hardness as well as fracture toughness. It also includes information on forming, heat treating, and machining. Filing Code: TS-367. Producer or source: Teledyne Vasco.


Alloy Digest ◽  
1980 ◽  
Vol 29 (7) ◽  

Abstract CPM REX 25 is a super high-speed steel made without cobalt. It is comparable to AISI Type T15 cobalt-containing high-speed steel in response to heat treatment, properties, and tool performance. CPM REX 25 is recommended for machining operations requiring heavy cuts, high speeds and feeds, and difficult-to-machine materials of high hardness and abrasion resistance. Typical applications are boring tools, drills, gear cutters, punches, form tools, end mills and broaches. This datasheet provides information on composition, physical properties, hardness, and elasticity as well as fracture toughness. It also includes information on forming, heat treating, machining, and surface treatment. Filing Code: TS-365. Producer or source: Crucible Materials Corporation.


2011 ◽  
Vol 130-134 ◽  
pp. 2245-2248
Author(s):  
Yong Hong Ma ◽  
Chong Xiang Zhang ◽  
Pan Zhang

we demonstrate a wavelength interleaved DWDM Radio-over-Fiber (ROF) system for providing 1-Gb/s OFDM signal in downlink and 1-Gb/s OOK data in uplink simultaneously. In this scheme, we use only one arrayed waveguide grating device at the remote node to realize both the de-multiplexing and multiplexing functions. The experimental results demonstrate that this scheme is feasible to the future broadband high-speed OFDM-ROF access system.


2014 ◽  
Vol 556-562 ◽  
pp. 3219-3222
Author(s):  
Shan Shan Li ◽  
Peng Wang ◽  
Xu Han ◽  
Jin Feng Liu ◽  
Xiao Gang Zhou

The supercavitation weapon is a new concept weapon moving at a high speed underwater, which is devised applying the characteristic of supercavitation reducing the resistance of water, and it may be widely used in the future. The present ventilating system has many shortcomings, such as less automation and numerous data cannot be measured and recorded timely. In this paper, the automatic monitor and control ventilating system of supercavitation water-tunnel was developed using configuration software and PLC. All parameters can be measured, recorded and displayed automatically via using of the system. It has many advantages such as higher automation, convenience, and easy maintenance.


1948 ◽  
Vol 15 (3) ◽  
pp. 248-255
Author(s):  
E. T. Habib

Abstract In mechanical gages used to measure the pressure from an underwater explosion, small copper cylinders are compressed at high speeds. This paper describes the test apparatus designed for the dynamic calibration of these cylinders, presents the results obtained with this apparatus, and compares these results with those obtained by other experimenters.


2021 ◽  
Vol 4 (1) ◽  
pp. 313-322
Author(s):  
V.I. Golik ◽  

The main directions of resource saving in the extraction of non-ferrous metals in Rus-sia are considered, the basis of which is the extraction of the useful component by leaching in underground blocks, piles and high-speed disintegrator mills. The current ideas about the problem are systematized and investigated, and a forecast of the use of resource-saving tech-nologies in the future is given.


1975 ◽  
Author(s):  
M. R. Garde

This paper presents a discussion on aircraft type gas-turbine train development. For railway traction purposes, the turbo-engines used on aircraft would improve the quality of the services provided in the electrified lines. The gas turbine should insure high speed and satisfactory acceleration. It would enable relatively lightweight construction to be carried out and run at a higher speed than trains on non-electrified lines. The gas turbine will not completely replace the diesel engine, but it will enable rolling stock to be constructed for which the diesel is unsuitable, especially in the case of high-speed, lightweight trainsets and, in the future, very high-powered units.


2001 ◽  
Vol 124 (2) ◽  
pp. 398-405 ◽  
Author(s):  
S. Yoshimoto ◽  
S. Oshima ◽  
S. Danbara ◽  
T. Shitara

In this paper, the stability of water-lubricated, hydrostatic, conical bearings with spiral grooves for high-speed spindles is investigated theoretically and experimentally. In these bearing types, pressurized water is first fed to the inside of the rotating shaft and then introduced into spiral grooves through feeding holes located at one end of each spiral groove. Therefore, water pressure is increased due to the effect of the centrifugal force at the outlets of the feeding holes, which results from shaft rotation. In addition, water pressure is also increased by the viscous pumping effect of the spiral grooves. The stability of the proposed bearing is theoretically predicted using the perturbation method, and calculated results are compared with experimental results. It was consequently found that the proposed bearing is very stable at high speeds and theoretical predictions show good agreement with experimental data.


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