In this paper, we solve the quadratic $alpha$-functional equations $2f(x) + 2f(y) = f(x + y) + alpha^{-2}f(alpha(x-y)); (0.1)$ where $alpha$ is a fixed non-Archimedean number with $alpha^{-2}neq 3$. Using the fixed point method and the direct method, we prove the Hyers-Ulam stability of the quadratic $alpha$-functional equation (0.1) in non-Archimedean Banach spaces.

abstract rockfill dams are usually used for affecting the flood and reducing the peak discharge. the materials used in these dams will usually make the flow turbulent, therefore darcy's law can not be used for this kind of dams and the equations based on the non-darcy flow must be applied. non-darcy flow equations are showed in two general ways including: and .one of the main parameters for flo...

nonlinear difference equations of higher order are important in applications; such equations appear naturally as discrete analogues of differential and delay differential equations which model various diverse phenomena in biology, ecology, economics, physics and engineering. the study of dynamical properties of such equations is of great importance in many areas. the autonomous difference equat...

in this paper, river regime equations through developing of unit stream power equation and based on data of sistan and karaj rivers were derived. at the first step, methods and out-comes of former researchers are classified. on the next step, based on dimensional analysis, unit stream power as a function of river flow parameters including suspended sediment load and specific gravity of particle...

We prove uniform existence results for the full Navier-Stokes equations for time intervals which are independent of the Mach number, the Reynolds number and the Péclet number. We consider general equations of state and we give an application for the low Mach number limit combustion problem introduced by Majda in [18].

A tentative suggestion is made that the flatness of the velocity derivative could reach an infinite value at finite (though very large) Reynolds number, with possible implications for the singularities of the Navier–Stokes equations. A direct test of this suggestion requires measurements at Reynolds numbers presently outside the experimental capacity, so an alternative suggestion that can be te...

We present a block preconditioner for LDG discretizations of Stokes equations. The dependence of its performance on the discretization parameters is investigated. An extension to Oseen equations is shown, yielding efficient and robust solvers in a wide regime of Reynolds numbers.

We give a condition for the periodic, three dimensional, incompressible Navier-Stokes equations to be globally wellposed. This condition is not a smallness condition on the initial data, as the data is allowed to be arbitrarily large in the scale invariant space B ∞,∞, which contains all the known spaces in which there is a global solution for small data. The smallness condition is rather a non...

This is a survey of some recent results on the existence of globally defined weak solutions to the Navier-Stokes equations of a viscous compressible fluid with a general barotropic pressure-density relation.