The unsteady flow of water to well in a layered aquifer with an interlayer flow is examined in this paper. The system studied comprises an aquifer consisting of two productive layers of finite thickness that are in a perfect hydraulic contact and a well which partially penetrates in one of the layers. Each layer is assumed to be homogeneous and isotropic and the water contained in the aquifer is of identical physical properties and small compressibility.The analytical solutions are derived for the case when the system is characterised by equality of hydraulic diffusivity of layers. These solutions give the results accurate enough for practical applications and allow to estimate the effects of partial penetration and contrast in parameters of formation on distribution of the flow potential both at large distances from wells and at the wells.The obtained solutions also provide a basis for predicting the interlayer flow arising from the performance of a pumping well as well as between a pair of wells which have an open interval located in different layers of the aquifer. Two cases have been analysed: (1) a pumping pair of wells which is used to prevent water inflow to the productive well, and (2) a pumping-injection pair of wells providing the demanded mixing of water from adjacent layers. Some examples of flow patterns and specially computed diagrams are given to illustrate the operation of such systems. 相似文献
In this paper, a mixing of gases through square Jets issuing normally Into a CrossFlow (JICF) is investigated by means of
both numerical simulation and experiment. The jets are emitted by two injectors mounted at the top and bottom of an Injector
Frame (IF) which is installed at the center of an Eiffel type wind-tunnel. This jet configuration makes it possible to approximate
an industrial gas mixer placed at the center of a pipe. Large Eddy Simulation based on the Smagorinsky model is used, enabling
characterization of the mean and fluctuating velocities as well as the oscillating flow frequencies. Different diagnostic
techniques, such as Laser Doppler Anemometry and Particle Image Velocimetry are employed for validating the numerical models,
and a good agreement between prediction and experiment is obtained. In the numerical simulation, introduction of a passive
scalar through the jet makes it possible to show three dilution phenomena. They are generated respectively by the wake of
the IF, the jet/wake assemblage and the jets alone in function of the momentum flux ratio between jet and crossflow. Influence
of the various parameters on the mixing process between the jets and the crossflow is identified. The numerical results show
that if the IF wake is suppressed with the presence of a trailing edge behind the IF, classical formation of Counter-rotating
Vortex Pair is found. 相似文献
The problem of the mixing of hot turbulent gases in an axisymmetric channel with a lateral surface of arbitrary shape and a pre-swirled flow is considered. The flowfields and the temperature and concentration distributions are calculated for various inlet conditions. 相似文献
Based on the previously formulated mathematical model of mechanics of a two-velocity two-temperature mixture of gases, the
evolution of an initially disturbed mixing layer of two gases with different densities under the action of shock waves is
considered in a two-dimensional unsteady approximation. Problems of interaction of shock waves with a sinusoidally disturbed
diffuse layer are solved numerically. The predicted variation of the mixing-region width are in satisfactory agreement with
experimental data.
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Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 46, No. 3, pp. 3–11, May–June, 2005. 相似文献
In this article we investigate turbulent flow of air through compound rectangular channels to experimentally investigate the turbulence phenomena in compound channels. Detailed experimental data of axial mean velocity, wall shear stresses, five of six Reynolds stresses, auto- and cross-spectral densities, and two-point space correlations were measured by hot-wire anemometry in 18 geometrical configurations.
The symmetry of the present flow appears to be better than that of previous measurements and the range of measurments is more extensive. The most interesting result is the existence of a quasi-periodic large-scale turbulence structure in most of the geometries investigated. This structure is stationary and independent of the axial position in the channel. It exists in any longitudinal slot or groove in a wall or a connecting gap between two flow channels, provided its depth is more than approximately twice its width. The frequency of this flow oscillation is determined by the geometry of the slot and is linearly dependent on the bulk velocity. 相似文献
The development of large-scale organised motions in a compressible mixing layer is studied experimentally using holographic
interferometry, pressure and turbulence measurements. The mixing layer was formed behind the base of a parallel strut with
a Mach 2 air main stream and a co-flowing two-dimensional slot jet (aspect ratio = 45) of helium at a Mach number of 1.2.
The mixing layer exhibited highly organised vortical structures which were elongated and inclined approximately 45–50° to
the flow direction. The mixing layer showed a linear growth and the mean velocity data indicated self-similar behaviour at
sufficiently downstream distances. The results have shown that the thickness of the primary boundary layer has a strong influence
on the growth and structure of the mixing layer.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献