In this paper, an upper bound approach is used to analyze the tube extrusion process through rotating conical dies with large mandrel radius. The material under deformation in the die and inside the container is divided to four deformation zones. A velocity field for each deformation zone is developed to evaluate the internal powers and the powers dissipated on all frictional and velocity disco...

The Failure on tube rod arm cylinder hydraulic excavator caused to lose production and processing time mining site. Investigation included visual inspection, chemical analysis, metallography analyze, microhardness test. Tube material used high silicon type while the standard ST52 carbon steel type. was broken crack several pieces. composition of has different in sulfur content. From hardness te...

Centrifugal air classifiers are one of the most used separation devices in particle technology. The study aims to obtain a detailed description bulk material classification mechanism developed centrifugal classifier. classifier design and stable vortex structure formation inter-tube space device described. Velocities within between vortices studied identify regions with inverse flows, which ser...

this research deals with axial and oblique impact crash tests on simple and hybrid composite tubes. axial and oblique impact tests have been generated on simple and hybrid composite tubes with one, two and three layers. a drop test rig was used to conduct the experiments. furthermore, in order to gain more detailed knowledge about the crash process, finite element simulations of the experiments...

This research deals with axial and oblique impact crash tests on simple and hybrid composite tubes. Axial and oblique impact tests have been generated on simple and hybrid composite tubes with one, two and three layers. A drop test rig was used to conduct the experiments. Furthermore, in order to gain more detailed knowledge about the crash process, finite element simulations of the experim...

Crash-dynamics research has always concentrated significantly in the safety, survivability of passengers a car crash. To identify capability energy absorption crash box, thin-walled structure will be modeled and simulated by ABAQUS software. Investigate influence material, cross-sectional, thickness factors on capacity tube, using MCDM – Multi-Criteria Decision-Making to get best option testing...

Pollen tube tip growth is a widely used model ideally suited to study cellular processes underlying polarized cell expansion. Local secretion supplying material for plasma membrane (PM) and cell wall extension is essential for this process. Cell wall biogenesis requires fusion of secretory vesicles with the PM at an about 10× higher rate than PM extension. Excess material is therefore incorpora...

In this paper free convection from a horizontal isothermal elliptic tube placed in a micropolar fluid with its major axis vertical is investigated. The governing equations are based on the conservation of mass, linear momentum, angular momentum and energy. The full governing equations written in stream function-vorticity formulation are solved numerically using the Spectral method based on Four...

Solidification of phase change materials encapsulated in a vertical shell which contains also the heat transfer fluid tubes is studied using a fixed grid numerical model. The solution of the system consists of adopting a velocity field of a complete developed flow coupled with the energy equations of the heat transfer fluid (HTF), the pipe wall and the phase change material (PCM). The control v...