Abstract

In this paper, a new perturbation technique is employed to solve strongly nonlinear Duffing oscillators, in which a new parameter α=α(ε)α=α(ε) is defined such that the value of α is always small regardless of the magnitude of the original parameter εε. Therefore, the strongly [...]

Abstract

The energy use in buildings has to be decreased to reach the targets and regulations in the European Union. One way of reducing the energy demand is to use vacuum insulation panels (VIP) in the building envelope. To make sure the declared thermal properties of the VIP are valid for [...]

Abstract

The motion of liquid filling a pipeline is impeded when the gas ahead of it cannot escape freely. Trapped gas will lead to a significant pressure build-up in front of the liquid column, which slows down the column and eventually bounces it back. This paper is an extension of previous [...]

Abstract

Liquid slugs have a relatively low mass and can therefore — when they occupy a full cross-section of a pipeline — be accelerated to very high velocities by means of pressurized gas. When entrapped gas pockets are present, pressures and temperatures may become dangerously high. [...]

Abstract

High pressures and high temperatures may arise in pipelines when a liquid column is suddenly accelerated into a gas pocket trapped at a closed end. A mass oscillation occurs that is described by nonlinear equations for both liquid and gas. Analytical expressions are derived for the [...]

Abstract

In the present investigation, an oscillating motion of unsteady Burgers fluid in a circular cylinder was modeled with different pressure waveforms. Three different waveforms are considered: the case of a trapezoidal, triangular and sinusoidal waveform. Analytical solutions of velocity [...]

Abstract

In this paper, an approximate analytical solution of the time fractional gas dynamics equation arising in the shock fronts, is obtained using a recent semi-analytical method referred as fractional reduced differential transform method. The fractional derivatives are considered in [...]

Abstract

The motion of liquid filling a pipeline is impeded when the gas ahead of it cannot escape. Entrapped gas will lead to a significant pressure build-up in front of the liquid column, which slows down the column and eventually bounces it back. The pressure and temperature in the gas [...]

Abstract

Improved one-dimensional (1D) models—compared to previous work by the authors—are proposed which are able to predict the velocity, length, and position of the liquid column in the rapid emptying and filling of a pipeline. The models include driving pressure and gravity, skin friction [...]

Abstract

In practice, the consolidation of soil around the pile has a great influence on the time-dependent bearing capacity of pile. However, most of the consolidation theory of soil around the pile neglects the disturbance effect of pile-driving on surrounding soil and regards the soil [...]