This paper presents the motion characteristics for high-speed catamarans travelling in waves. Two mathematical models, threedimensional translating-pulsating source distribution technique and three-dimensional pulsating source distribution technique, are used for predicting the motions of the wave-piercing catamaran in oblique waves. The comparison between numerical predictions and experimental...

A current-voltage characteristic of direct current (DC) gas discharge operated in a micro gas jet injected into a secondary electron microscope (SEM) chamber is presented. Ar gas was injected through a 30 μm orifice gas nozzle (OGN) and was evacuated by an additional pump to keep the high vacuum environment. Gas discharges were ignited between the OGN as anode and a counter electrode of Si wafe...

In their recent topical review, Nabavi and Siddiqui (Meas. Sci. Technol. 2010 21 042002) recommended the use of hot-wire anemometry for velocity measurements in pulsating flows, especially at high frequency. This recommendation is misleading. The procedures invoked by these authors are valid only for small-amplitude fluctuations, which are of little interest for pulsating flows. When large-ampl...

The demands to automatic control for industrial plants are growing due to an increased complexity of the manufacturing processes. To face these challenges, intelligent control is getting more and more important. For example, neural networks and fuzzy logic are regularly used. The usage of Bayesian networks is seldom mentioned even if many training algorithms are available and Bayesian networks ...

We describe flight variability in the woodwasp Sirex noctilio Fabricius, 1793 (Hymenoptera: Siricidae) by studying tethered females in a flight mill device and analyzing output data by a time series methodology. Twenty-eight wasps were flown during 24 h-long periods, under controlled temperature and lighting conditions. The maximum distance recorded was 49 km, and mean velocity was 0.37 m s(-1)...

Die corner filling is very important in tube hydroforming process. Definition of the internal pressure path is a key factor in improving the corner filling.  However, the factors that cause improvement of corner filling are still unclear. In this paper, effect of bilinear pressure path on corner filling in hydroforming of tube in box-shape die is studied using both finite element simulation and...

Tube hydroforming (THF) process is used to produce the complex components from the initial cylindrical tubes. In this paper, T- shape component was formed using a tube hydroforming machine and the residual stresses of hydroformed tube was determined by hole drilling method. Subsequently, the thickness distribution and residual stresses of final tube were investigated using experimental and fini...

One of the bellows producing method is hydroforming process .Whereas some factor of hydroforming process specially internal pressure affects on final characteristics produced bellows such as bursting, wrinkling and wall thickness distribution. In this paper the effect of internal pressure factor in final quality of produced bellows will be investigated. In simulation of process, ABAQUS/Explicit...