This paper considers the classical problem of the steady boundary layer flow past a semi-infinite flat plate first considered by Blasius in 1908 with generalized surface slip velocity. Numerical solutions are obtained by solving the nonlinear similarity equation using the bvp4c function from MATLAB for several values of the slip parameters.

The North Tabriz Fault (NTF) is an active fault which poses a high seismic hazard to the areas of NW Iran, especially the city of Tabriz with a population of 1.6 million. In order to determine the geometry and the kinematics of this fault system, a local dense seismological network including forthy 3-component stations was installed around the central segment of Tabriz Fault which crosses the northern part of the city of Tabriz. This network operated for 3 months. Using microearthquakes recorded by our temporary network in addition of more than 6 years of local events recorded by 8 permanent stations of Tabriz telemetry network, the 1-D crustal velocity of the region was determined. Our results indicates that the upper crust consists of a ~6 km thick sedimentary layer (VP = 5.23 km s-1) overlying a ~18 km thick upper crystalline crust (VP = 5.85 km s-1). We estimate a velocity of 6.54 km s-1 for the lower crystalline crust, but the limited focal depths of our local events did not allow determining the thickness of this layer. The well-located earthquakes indicate the seismic activity along the Tabriz fault. Precise examination of the focal depths on different cross sections indicates that the western and central segment of this fault system dip northeast ward while the eastern part shows almost southwest dipping plane. Calculated focal mechanism all indicates the right-lateral strike-slip motion of the Tabriz Fault. The most reliable fault plane solutions are consistent with cross sections showing evidence of extension in Eastern part comparing to compression observed in Western segment. Our focal mechanisms and geodetic studies using GPS measurements indicate that the North Tabriz Fault helps to northeast motion of trapped crust in this area. 

The steady-state fully-developed laminar flow of non-Newtonian power-law fluids is examined in a circular microchannel with slip boundary condition and under an imposed constant wall heat flux. Effects of slip as well as the hydrodynamic and thermal key parameters on heat transfer and entropy generation are investigated. The results reveal that increasing the Brinkman number and the flow behavior index both lead to increasing the entropy generation and decreasing the Nusselt number. In heating process, the temperature difference between the fluid and the wall decreases as the slip coefficient increases; similar trend may or may not be observed for cooling process, determined by the range of the slip coefficient as well as the Brinkman number. An increase in the slip coefficient leads to an increase in both the Nusselt number and the Bejan number, whereas it gives rise to a decrease in entropy generation. For each particular value of the slip coefficient, the Nusselt number approaches a specific value as the Brinkman number and/or the flow behavior index increases. An increase in the flow behavior index or a decrease in the slip coefficient results in incrementing the average entropy generation.

Please click on PDF to view the abstract

Dynamic motion of a 2D SD7037 airfoil is investigated numerically in presence of a slip boundary condition. The dynamic motion of the airfoil is a harmonic oscillation, where the frequency and the amplitude of oscillations were adequate to airfoil to undergoing dynamic stall phenomenon. Dynamic stall occurred when the dynamic motion of the airfoil causes dynamic stall vortices, resulting in leading edge and trailing edge vortices which lead to rising the aerodynamic loads significantly. Analyzing the phenomena is challenging especially when a slip boundary condition exists near the airfoil wall. This particular condition is the general property of super-hydrophobic surfaces. These surfaces could potentially prevent the blade from icing. The main characteristic of these coatings is the appearance of a slip velocity on the wall. The slip velocity can affect the airfoil aerodynamics which is the main purpose of this paper. In this regard, a 2D airfoil with the Reynolds number of Re≈ 4×〖 10〗 ^4 is analyzed using computational fluids dynamics (CFD). The Transition-SST model is applied. The results showed that not only the slip condition affects the aerodynamic loadings, but also the dynamic stall regimes changed considerably. So that for slip lengths higher than 100 micrometers, the maximum magnitude of the lift coefficient damped by 16%.

In this paper, a modified adaptive nonlinear filter (MANF) to estimate the vehicle longitudinal velocity of the vehicle has been presented which has acceptable accuracy and simple structure. Obtaining accurate model with minimum uncertainty is difficult and almost impossible, consequently, conventional model based filters cannot be used simply in estimating the longituadinal velocity of the vehicle during the braking.On the other hand, the model based filters require the braking toque in velocity estimation where, measuring the braking torque requires specific sensors which will cause increasing the costs of repairing and maintenance.Consequently, in this paper a MANF has been introduced which didn’t require the dynamic model of vehicle and the value of braking torque in estimation process. MANF has been evaluated by experimental data and its effectiveness has been approved.

The slurry pump, which forms the core equipment of the deep-sea mining (DSM) system, provides lifting power for the ore from the seabed to the sea level, which is crucial for the safety of coarse ore particle transportation. Velocity slip plays a significant role in revealing the migration of the pump particles. Therefore, this study analyzes the velocity slip in a slurry pump using the computational fluid dynamics–discrete element method (CFD-DEM) for the first time. The relationship between the pump head and velocity slip was proposed and verified in this study based on the velocity triangle and Euler equation of the solid-liquid two-phase flow in the impeller. The effects of different particle sizes on the velocity slip are compared in detail. According to the computational results, the head depends on the larger velocity slip of the impeller outlet and lower velocity slip at the inlet. The peak value of the velocity slip was significantly reduced, and the peak position of the velocity slip and zero-point position moved backward for particle sizes ranging between 5-15 mm. This study provides a reference for the problems of particle migration and velocity slip in slurry pumps.