A dimension split method for the incompressible Navier-Stokes equations in three dimensions

2013 ◽  
Vol 73 (5) ◽  
pp. 409-435 ◽  
Author(s):  
H. Chen ◽  
K. Li ◽  
S. Wang
Author(s):  
S. G. Rajeev

The initial value problem of the incompressible Navier–Stokes equations is explained. Leray’s classic study of it (using Picard iteration) is simplified and described in the language of physics. The ideas of Lebesgue and Sobolev norms are explained. The L2 norm being the energy, cannot increase. This gives sufficient control to establish existence, regularity and uniqueness in two-dimensional flow. The L3 norm is not guaranteed to decrease, so this strategy fails in three dimensions. Leray’s proof of regularity for a finite time is outlined. His attempts to construct a scale-invariant singular solution, and modern work showing this is impossible, are then explained. The physical consequences of a negative answer to the regularity of Navier–Stokes solutions are explained. This chapter is meant as an introduction, for physicists, to a difficult field of analysis.


1991 ◽  
Vol 43 (6) ◽  
pp. 1161-1212 ◽  
Author(s):  
G. F. D. Duff

AbstractFor a vector solution u(x, t) with finite energy of the Navier Stokes equations with body forces and boundary values on a region Ω ⊆ R3 for t > 0, conditions are established on the L6/5(Ω) and L2(Ω) norms of derivatives of the data that ensure the estimates and max , up to any given integer value of the weighted order 2r+s, where r or s = s1 + s2 + s3 > 0 and 0 < T < ∞.


Water ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 82
Author(s):  
Getnet Kebede Demeke ◽  
Dereje Hailu Asfaw ◽  
Yilma Seleshi Shiferaw

Hydraulic structures are often complex and in many cases their designs require attention so that the flow behavior around hydraulic structures and their influence on the environment can be predicted accurately. Currently, more efficient computational fluid dynamics (CFD) codes can solve the Navier–Stokes equations in three-dimensions and free surface computation in a significantly improved manner. CFD has evolved into a powerful tool in simulating fluid flows. In addition, CFD with its advantages of lower cost and greater flexibility can reasonably predict the mean characteristics of flows such as velocity distributions, pressure distributions, and water surface profiles of complex problems in hydraulic engineering. In Ethiopia, Tendaho Dam Spillway was constructed recently, and one flood passed over the spillway. Although the flood was below the designed capacity, there was an overflow due to superelevation at the bend. Therefore, design of complex hydraulic structures using the state-of- art of 3D hydrodynamic modelling enhances the safety of the structures. 3D hydrodynamic modelling was used to verify the safety of the spillway using designed data and the result showed that the constructed hydraulic section is not safe unless it is modified.


Author(s):  
Adrian Sescu ◽  
Brett Andersen ◽  
Abdollah A. Afjeh

In this paper, a Computational Fluid Dynamics (CFD) analysis of tower shadow effect associated with downwind configuration horizontal axis wind turbines (HAWT) is presented. This work is part of a large project focused on the design and installation of a multi-megawatt, downwind configuration, offshore HAWT in Lake Erie. The numerical tool is a dedicated commercial CFD solver, capable of performing accurate simulations in three dimensions, by solving the Navier-Stokes equations in turbulent regime. The tower shadow effect is analyzed by comparing results from the downwind configuration to results from the corresponding upwind configuration and free rotor.


Author(s):  
Manil T. Mohan ◽  
Sivaguru S. Sritharan

In this paper, we study the stochastic Navier–Stokes equations (SNSE) perturbed by Lévy noise in three dimensions with a hereditary viscous term which depends on the past history. We establish the local solvability of the Cauchy problem for such systems. The local monotonicity property of the nonlinear term of the cutoff problem and a stochastic generalization of the Minty–Browder technique are exploited in the proofs. Finally, we show that the global solvability results hold under smallness condition on the initial data and suitable assumptions on the noise coefficients.


Author(s):  
R. S. Solomatin ◽  
◽  
I. V. Semenov ◽  
◽  
◽  
...  

A numerical model of the turbulent mixing process between two parallel supersonic flows is considered. Model problem of hydrogen injection into the inert gas flow with Mach number M = 2.44 in the Burrows-Kurkov combustor is simulated in two and three dimensions for validating the Spalart-Allmaras (SA) turbulence model and diffusion model computational algorithms for multicomponent gas mixture. The system of averaged Navier-Stokes equations, closed with the turbulence model equation, is solved with the hybrid explicit-implicit LU-SGS-GMRES algorithm. Obtained results are compared with experimental and computational data.


Sign in / Sign up

Export Citation Format

Share Document