Motivated by recent experiments, numerical simulations were performed of cylindrically converging shock waves. The converging shocks impinged upon a set of zero to sixteen regularly space obstacles. For more than two obstacles the resulting diffracted shock fronts formed polygonal shaped patterns near the point of focus. The maximum pressure and temperature as a function of number of obstacles ...

This paper considers the turbulent-flow characteristics and the mechanism of vortex shedding behind one and two square obstacles centered inside a 2-D channel. The investigation was carried out for a range of Reynolds number (Re) from 1 to 300 with a fixed blockage ratio β = 0.25. Comparison of the flow patterns for the single and two obstacles was feasible. The computations were based on the f...

Particle diffusion in the presence of sparse obstacles may be considered as a sequence of relatively long intervals, during which the particle diffuses in regions free of obstacles, separated by relatively short intervals during which the particle suffers multiple collisions with an obstacle. The present paper focuses on the mean duration of the short intervals, called mean encounter time, assu...

The goal is to collect pearls (small golden circles) by sliding a droplet of water (large blue circle) over them in a grid map. The map contains obstacles (square blocks). In each move, the droplet slides in one of the four directions to the maximal extent, until it is stopped by an obstacle. 7 Moves! left (1st pearl) up, left (2nd pearl) down, right, up, left (3rd pearl) The map contains only ...

background and purpose: physical activity may be classified as intense, moderate, and low. despite their health-related benefits, iranian women have a low rate of physical activity. women face numerous obstacles and challenges for participating in physical activity programs, most notably are household chores and taking caring of children, long distance between home and workplace and the other p...

This paper examines the obstacles of marriage and analyzes the tendency towards marriage in Hamedan Province. This paper uses survey data required a sample of 400 young individuals by using a multistage cluster sampling and stratified random sampling. The main obstacles of marriage in this study in terms of priority, were cultural obstacles with an average rank (4.94), social obstacles with an ...

To understand the propagation characteristics of methane-air deflagration flames and in an obstacle-filled tube, a high-speed color video camera, photoelectric sensors, and pressure transducers were used to test the deflagration flame propagating parameters. The tests were run in a 1500 mm long plexiglass tube with a 100 × 100 mm square cross-section. The obstacles included four types of repeat...

We take some parts of a theoretical mobility model in a two-dimension grid proposed by Greenlaw and Kantabutra to be our model. The model has eight necessary factors that we commonly use in a mobile wireless network: sources or wireless signal providers, the directions that a source can move, users or mobile devices, the given directions which define a user’s movement, the given directions whic...