.hot metal gas forming of tubes can be used in various industries such as automotive and aerospace industries. in this process tube is formed at elevated temperatures, by using gas instead of fluid pressure. lower required pressure and low power are its advantages in comparison to hydroforming process. in this paper, a hot metal gas bulging process of an aluminum alloy tube has been investigate...

A computational study has been carried out to assess the influence of pressure on the flow behaviors in dense gas-fluidized beds. Therefore the discrete particle simulation approach has been employed to study the regime transitions, local two-phase flow structures and the energy dissipation distribution. The results show that high pressure reduces the incipient fluidization velocity, widens the...

The Galerkin method is applied to analyze the elastic large deflection behavior of metal plates subject to a combination of in-plane loads such as biaxial loads, edge shear and biaxial inplane bending moments, and uniformly or nonuniformly distributed lateral pressure loads. The motive of the present study was initiated by the fact that metal plates of ships and ship-shaped offshore structures ...

A redshift-magnitude relation for the two exact non-uniform pressure spherically symmetric Stephani universes is presented. The Kristian-Sachs method expanding the relativistic quantities in series is used, but only first order terms in redshift z are considered. The numerical results are given both for centrally placed and non-centrally placed observers. In the former case the redshiftmagnitud...

Presented here are observations that demonstrate how the deformation of millimetric cavitation bubbles by a uniform pressure gradient quenches single-collapse luminescence. Our innovative measurement system captures a broad luminescence spectrum (wavelength range, 300-900 nm) from the individual collapses of laser-induced bubbles in water. By varying the bubble size, driving pressure, and perce...

The results obtained from the experimental testing of hoop wound S-2 GlasdEpoxy and AS41 PPS composite rings are presented here. In this study, the effects of different material system and thickness on failure are investigated. A custom, volume controlled pressurization set-up was designed and built for the tests. Initial imperfection in the ring specimens were measured prior to testing and the...

Effect of clamping pressure on electrical resistance between Gas diffusion layer (GDL) and bipolar plate is a very important parameter in Proton exchange membrane (PEM) fuel cells. For investigation of this matter some researches have been done in these years. But there is not an experimental investigation of clamping pressure effect on PEM electrical resistance. In this paper, some experimenta...

In recent years, hydroforming process has been applied in different industries such as aerospace, automotive and military industries due to its advantages, such as high dimensional accuracy, capability of forming complicated parts and high drawing ratio. Hydrodynamic deep drawing with radial pressure is one type of hydroforming process. In this paper, forming of cylindrical cups in hydrodynamic...

A plate-fin heat exchanger is a type of heat exchanger widely used in air conditioners, and tubes and fins are tightly assembled by the mechanical expansion process of tubes. The tube expansion process deforms the grooves inside the tube, and the groove shapes also affect the adhesion between tubes and fins. In this study, the adhesion and heat transfer performance affected by the tube expansio...