In this paper analytical expressions for time-dependent velocity profiles and pressure gradient are obtained for fully-developed laminar flows with given volume flow-rate conditions in circular pipe flows with slip boundary conditions. The governing equations are solved analytically using the traditional Laplace transform method together with Mellin’ s inversion formula. The evolution of velocity profiles and pressure gradient for starting and pulsatile flow with slip boundary conditions are analyzed. New simplified expressions and perspectives on velocity and pressure gradient for no-slip and slip flows are obtained from the analytical results. New scalings in starting and pulsatile flows are proposed for pipe flows with no-slip and slip boundary conditions using nondimensional numbers. Special attention is paid to the effect of slip factor and pulsatile flow frequency on the time-dependent skin-friction factor. Finally, by using the starting and pulsating flow results, analytical expressions of velocity and pressure for arbitrary inflow are obtained by approximating the arbitrary volume flow-rate by a Fourier series.

Boundary conditions play a key role in dynamic response and modal characteristics of mechanical structures. Since modeling and dynamic analysis of real structures containing real boundary conditions and joints is a difficult task to do in structural dynamics, it is important to have accurate dynamic models for boundary conditions and joints. Many methods proposed for identification of joints or boundary condition parameters in the past. It is worth mentioning that having an accurate physical understanding of the structure is vital in successfully using the identification methods. ….

This paper concerns with the boundary layer flow and heat transfer over a permeable stretching/shrinking sheet in a viscous fluid, with the bottom surface of the plate is heated by convection from a hot fluid. The partial differential equations governing the flow and heat transfer are converted into ordinary differential equations using a similarity transformation, before being solved numerically. The effects of the suction, convection and stretching/shrinking parameters on the skin friction coefficient and the local Nusselt number are examined and graphically illustrated. Dual solutions are found to exist for a certain range of the suction and stretching/shrinking parameters. The numerical results also show that suction widens the range of the stretching/shrinking parameter for which the solution exists.

In this paper, the present investigation has been conducted keeping in mind some of the problems concerning the crack propagation direction and growth under constant loading in an inclined crack geometry. The present studies mainly focused on the development and modifications in the crack growth criterion to account the biaxial, shear loading and number of stress terms. Existing criteria for the prediction of crack initiation direction have been modified taking higher order stress terms. The effective methods of experimentally determining the stress intensity factor for a body containing a crack is to analyze the isochromatic pattern obtained from a photoelastic model. The effect of biaxial load factor, crack angle, Crack length/width of specimen and length of specimen/width of specimen were studied and a regression model was developed for geometry correction to predict stress intensity factor for tearing mode and intensity factor for shearing mode. This approach is being used to predict crack growth trajectory under biaxial cyclic loading by assuming that the crack may grow in a number of discrete steps using the vectorial method. MTS criterion (Maximum Tangential Stress criterion) is used for prediction of crack initiating angle. The crack growth trajectory has been determined by cycle simulation procedure.

Due to the geometrical similarity to many engineering structures, the flow characteristics around the square cylinder have been studied for some time using the experimental or Computational Fluid Dynamics (CFD) technique. However in the past research the inlet boundary is assumed to be steady for simplifying the simulation model, which is conflict with real flow field. To overcome such problem, in this paper, the time varying inlet boundary condition based on autoregressive moving average (ARMA) model is proposed, based on which this inlet boundary generation procedure is introduced. To study the flow characteristics around the square cylinder, a 2D large eddy simulation procedure numerical description is introduced, and different turbulence intensity will be considered at the inlet boundary. The general aerodynamic parameters such as lift coefficient and drag coefficient and velocity component time averaged values along the centre line of the computational domain are discussed. To study the aerodynamic parameters in the frequency domain, the velocity spectrum at different position around the square cylinder will be discussed.