We consider some typical optimal control problems for a nonlinear model of longitudinal vibrations in a viscoelastic rod. In trying to follow the usual pattern of showing that every innmizing sequence of controls contains a subsequence suitably converging to an optimal control, we confront the severe technical diiculty that the constitutive function cannot be uniformly Lipschitzian in its argum...

When a natural gas pipeline ruptures, the adjacent automatic line control valves (ALCVs) should close quickly to prevent leakage or explosion. The differential pressure set point (DPS) at each valve location is the main criteria for value setting in ALCV action. If the DPS is not properly adjusted, the ALCV may mistakenly close or it may not take any action at proper time. This study focused on...

Control of flow past a circular cylinder using rotating control rod is investigated by conducting two-dimensional numerical simulations with Reynolds number 200, rod-to-cylinder diameter ratio 0.2, gap position angles the between 0° and 180°, rotation rates −7 7. The rate positive if rotates in anticlockwise direction. aim this paper to discover effects angle on control. If placed at side (posi...

A rectangular rod is placed in a flow field flowing parallel to a flat plate. Effect of chord-thickness ratio of rectangular rod on developing vortex shedding downstream to the rod is studied. Then, for each one of the aspect ratios, the distance of the rod from the neighboring flat plate is reduced until the rod sticks to the flat plate. In each case, the effect of the flat plate boundary laye...

Several studies have shown that the satisfactory oil well operations with sucker-rod pumps is attributed to the techniques and methods which are able to control the performance of the well. However, the presence of uncertainties in the sucker-rod dynamical models or parameter variations may jeopardize the desired performance of the control system and the rod pump system productivity. These para...

When a natural gas pipeline ruptures, the adjacent upstream and downstream automatic control valves (ACV) should close quickly to prevent leakage or explosion. The differential pressure set point (DPS) at each valve location is the main criteria for value setting in ACV actions. If the DPS is not properly adjusted, the ACV may mistakenly close or it may not take any actions at a proper ti...