A new approach to flow problems past a screen

1985 ◽  
Author(s):  
O. INOUE ◽  
K. KUWAHARA
Keyword(s):  
1951 ◽  
Vol 3 (3) ◽  
pp. 193-210 ◽  
Author(s):  
M.J. Lighthill

SummaryThe general technique for rendering approximate solutions to physical problems uniformly valid is here applied to the simplest form of the problem of correcting the theory of thin wings near a rounded leading edge. The flow investigated is two-dimensional, irrotational and incompressible, and therefore the results do not materially add to our already extensive knowledge of this subject, but the method, which is here satisfactorily checked against this knowledge, shows promise of extension to three-dimensional, and compressible, flow problems.The conclusion, in the problem studied here, is that the velocity field obtained by a straightforward expansion in powers of the disturbances, up to and including either the first or the second power, with coefficients functions of co-ordinates such that the leading edge is at the origin and the aerofoil chord is one of the axes, may be rendered a valid first approximation near the leading edge, as well as a valid first or second approximation away from it, if the whole field is shifted downstream parallel to the chord for a distance of half the leading edge radius of curvature ρL. It follows that the fluid speed on the aerofoil surface, as given on such a straightforward second approximation as a function of distance x along the chord, similarly is rendered uniformly valid (see equation (52)) if the part singular like x-1 is subtracted and the remainder is multiplied by .


1949 ◽  
Vol 1 (06) ◽  
pp. 325-332 ◽  
Author(s):  
H. Godwin

Abstract The author describes the work of Dr. V. Vareschi on the pollen content of glacier ice. A general account of the method of analysis is given. The results of statistical evidence of the analyses on several alpine glaciers are discussed, particularly in regard to the general nature of glacier flow in different parts of the glaciers. Vareschi’s suggestions as to the modes of origin of a certain type of ogive banding and of parallel banding (Pflugfurcheneis) are dealt with in the light of his findings. It is pointed out that what appears to be a valuable new approach to the solution of glacier flow problems needs elaboration before it can be accepted in all its bearings.


1994 ◽  
Vol 262 ◽  
pp. 171-204 ◽  
Author(s):  
Andrew J. Szeri ◽  
L. Gary Leal

A numerical investigation is conducted into the flow of a dilute suspension of rigid rod-like particles between parallel flat plates, driven by a uniform pressure gradient. The particles are assumed to be small relative to lengthscales of the flow with the effect that particle orientations evolve according to the local velocity gradient; the particles are also assumed to be small in an absolute sense, with the consequence that Brownian motions are of consequence. The calculations are performed using a novel approach, with a theoretical basis that has been developed previously in a companion paper (Szeri & Leal 1992). The new approach permits one to solve flow problems of microstructured fluids (such as suspensions, liquid crystals, polymer solutions and melts) without ‘pre-averaging’ or closure approximations. In the present work, the new approach is used to expose previously unknown pathological, non-physical predictions in various constitutive models derived using closure approximations. This appears to have passed unnoticed in prior work. In addition, the new approach is shown to possess several computational advantages. The determination of the orientation distribution of particles is self-adaptive; this leads, in effect, to a very efficient solution of the associated Smoluchowski (or Fokker–Planck) equation. Moreover, the new approach is highly suited to parallel (and vector) implementation on modern computers. These issues are explored in detail in the context of the example flow.


2019 ◽  
Vol 14 (3) ◽  
pp. 313 ◽  
Author(s):  
Abdon Atangana ◽  
Rubayyi T. Alqahtani

One of the major problem faced in modeling groundwater flow problems is perhaps how to capture heterogeneity of the geological formation within which the flow takes place. In this paper, we suggested applied a newly established approach to model real world problems that combines the concept of stochastic modeling in which parameters inputs are converted into distributions and the time differential operator is replaced by non-local differential operators. We illustrated this method with the Earth equation of groundwater recharge. For each case, we provided numerical and exact solution using the newly established numerical scheme and Laplace transform. We presented some numerical simulations. The numerical graphical representations let no doubt to think that this approach is the future way of modeling complex problems.


AIAA Journal ◽  
1985 ◽  
Vol 23 (12) ◽  
pp. 1916-1921 ◽  
Author(s):  
Osamu Inoue

1949 ◽  
Vol 1 (6) ◽  
pp. 325-332
Author(s):  
H. Godwin

AbstractThe author describes the work of Dr. V. Vareschi on the pollen content of glacier ice. A general account of the method of analysis is given. The results of statistical evidence of the analyses on several alpine glaciers are discussed, particularly in regard to the general nature of glacier flow in different parts of the glaciers. Vareschi’s suggestions as to the modes of origin of a certain type of ogive banding and of parallel banding (Pflugfurcheneis) are dealt with in the light of his findings. It is pointed out that what appears to be a valuable new approach to the solution of glacier flow problems needs elaboration before it can be accepted in all its bearings.


2018 ◽  
Vol 32 (12n13) ◽  
pp. 1840012 ◽  
Author(s):  
Qi-Feng Wu ◽  
Chang Shu ◽  
Yan Wang ◽  
Li-Ming Yang

The recently proposed lattice Boltzmann flux solver (LBFS) is a new approach for the simulation of incompressible flow problems. It applies the finite volume method (FVM) to discretize the governing equations, and the flux at the cell interface is evaluated by local reconstruction of lattice Boltzmann solution from macroscopic flow variables at cell centers. In the previous application of the LBFS, the structured meshes have been commonly employed, which may cause inconvenience for problems with complex geometries. In this paper, the LBFS is extended to arbitrarily unstructured meshes for effective simulation of incompressible flows. Two test cases, the lid-driven flow in a triangular cavity and flow around a circular cylinder, are carried out for validation. The obtained results are compared with the data available in the literature. Good agreement has been achieved, which demonstrates the effectiveness and reliability of the LBFS in simulating flows on arbitrarily unstructured meshes.


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