Showing papers on "Obstacle published in 1977"

A numerical method for stratified shear flows over a long obstacle

Abstract: The nonlinear problem of steady flow of an incompressible stratified fluid of finite depth over an obstacle is investigated by using a numerical algorithm which solves both obstacle height and flow fields simultaneously instead of solving the flow fields, given the obstacle height. We also find, for a given upstream condition, a maximum obstacle height over which steady flows are possible, not allowing discontinuities or closed streamlines. This maximum height is a functional of the upstream density stratification and the velocity shear. We calculate this functional dependence for a number of specific upstream conditions. It is also shown that the number of layers required in the model to represent a flow field increases as the Froude number decreases or as the vertical wave number increases. The hydrostatic and finite depth assumptions are essential in our method.

Vehicle collision preventing apparatus

Abstract: A vehicle collision preventing apparatus determines the danger by an output of a radar for detecting the distance to an obstacle and the relative velocity in a danger determining circuit wherein the distance to the obstacle and the relative velocity at the present are estimated from the data given before disappearing the data of the radar by an estimate arithmetic circuit when a signal reflecting from the obstacle reduces to be incapable of detecting the obstacle by the radar.

Control system of mover

Abstract: PURPOSE:To make it possible for a car to run neither being hindered by obstacle such as a metal plate etc. on a driving lane nor providing a detour.

Film Thickness in Gas-Liquid Two Phase Flow : 2nd Report, Effect of four-rectangular-obstacle inserted into tube

Abstract: An additional experiment was made of the effects of flow obstacle on minimum film thickness in gas-liquid two-phase upward flow. The obstacle used in this experiment consists of four rectangular shaped pieces jutting from the inner surface of the tube. The results suggest that the present type of obstacle also has strong effects on the film thinning process upstream of the obstacle, which are similar to those of the circular ring used as the obstacle in the 1st report. However, because the liquid film can flow between the pieces, a reverse flow across the obstacle is easy to occur during the drainage period existing at low air velocities, and the amount of liquid accumulated below the obstacle at relatively high air velocities is reduced. On account of these effects, the minimum film thickness upstream of the obstacle increases at low air velocities and decreases at high air velocities. On the other hand, the minimum film thickness in the downstream region is almost the same as that without obstacle.

Data transmission system

Abstract: PURPOSE:To make it possible to transmit data without suffering noisy obstacle, by using the twisted cable in case the data quantity is comparatively a little.

Radio wave imaging by an obstacle scanning

Abstract: A new radio-wave imaging technique was demonstrated with a 9.43 GHz microwave, where an obstacle was scanned in the plane before or behind objects placed in the radiation field and the radio-wave signals disturbed by the obstacle were displayed by a CRT as shadow images.