in many industrial equipment such as boilers and heat exchangers, the cylindrical tubes are exposed to the gas- liquid two phase flow. for any immersed body in flow field vortex shedding is created with a frequency that may be constant or variable, according to conditions such as flow rates, geometry of body, and etc. the failure will happen in the equipment, when this frequency is close to one...

We study the flux tube junctions in the limit of large magnetic flux. In this limit the flux tube becomes a wall vortex which is a wall of negligible thickness (compared to the radius of the tube) compactified on a cylinder and stabilized by the flux inside. This wall surface can also assume different shapes that correspond to soliton junctions. We can have a flux tube that ends on a wall, a fl...

In this study, a functional vest which can be worked by manuel without any starting system was designed and a prototype was produced for peoples cooling requirement. This system was made of a vortex tube, knee pad, linear motion mechanism with 3 members and vest. While walking, depending on knee’s movement, a piston at linear motion mechanism was moved front and backward. This front and back mo...

Formation of vortex rings at the exit of a shock tube is studied theoretically. A model for predicting the maximum circulation that a vortex ring can attain at the exit of a shock tube is offered. To achieve maximum circulation the initial conditions and the design of the driver and driven sections must be such that the generated shock wave reaches the shock tube exit at least 4Dn/^2 time units...

A numerical model of axisymmetric convection in the presence of a vertical magnetic flux bundle and rotation about the axis is presented. The model contains a compressible plasma described by the nonlinear MHD equations, with density and temperature gradients simulating the upper layer of the sun’s convection zone. The solutions exhibit a central magnetic flux tube in a cylindrical numerical do...

Vortex shedding may occur in tube arrays, resulting in strong excitation forces at discrete frequencies. In the past the Strouhal numbers governing vortex shedding in these systems were determined primarily by experiment. This paper presents a computationally inexpensive method of numerical simulation for the unsteady flow through a rigid normal triangular tube array which determines both the f...

The present study aimed to develop a quick and efficient method for purification of newborn endothelial cells from tumor tissues. Fresh tissues were separated from C57BL/6 mice bearing tumors derived from mouse lung cancer Lewis cells, fully minced and divided into two parts. One part was subjected to collagenase type I digestion with a vortex to form a single-cell suspension, while another par...