| ATTRIBUTE | VALUE |
|---|---|
| type | C |
| database id | 7852 |
| title | |
| authors | |
| affiliations | |
| year | 2011 |
| series | Archives of Hydro-Engineering and Environmental Mechanics |
| issue | Vol. 58, No. 1-4 |
| publisher | Wydawnictwo IBW PAN |
| place | Gdańsk |
| attributes | [published] [reviewed] [scientific] [international reach] |
| language | en |
| ATTRIBUTE | VALUE |
|---|---|
| type | A |
| database id | 7719 |
| title | Simulation of solitary wave mechanics by a corrected smoothed particle hydrodynamics method |
| authors | Staroszczyk R. |
| pages | 23 — 45 |
| full text link | http://www.ibwpan.gda.pl/storage/app/media/ahem/ahem58str023.pdf |
| keywords | solitary wave, non-linear wave interaction, meshfree Lagrangian method, smoothed particle hydrodynamics |
| affiliations | |
| abstracts | The paper is devoted to numerical modelling of solitary wave propagation phenomena in shallow water of uniform depth. The problem governing equations are solved by applying a corrected smoothed particle hydrodynamics (SPH) method in which standard smoothing kernel functions are modified in such a way that so-called linear reproducing conditions for kernel approximations and their first-order spatial derivatives are satisfied. Numerical performance of the proposed SPH model has been verified by comparing its predictions with analytical results for a solitary wave travelling over the horizontal bottom. Also, the results obtained by applying the corrected SPH method and those given by the standard SPH method, with no kernel correction, are compared. Further, an impact of the solitary wave on a vertical rigid wall is investigated, and finally an interaction of two colliding solitary waves is considered. |
| attributes | [reviewed] [scientific] |
| language | en |
| ATTRIBUTE | VALUE |
|---|---|
| type | A |
| database id | 7650 |
| title | Boussinesq-type equations for long waves in water of variable depth |
| authors | Szmidt J. K. |
| pages | 3 — 22 |
| notes | Kopia w oprac. wew. Tp4232 |
| full text link | http://www.ibwpan.gda.pl/storage/app/media/ahem/ahem58str003.pdf |
| keywords | long waves, wave propagation, variable water depth |
| affiliations | |
| abstracts | The paper deals with the problem of the transformation of long gravitational waves propagating in water of variable depth. The main attention of the paper is focused on the derivation of equations describing this phenomenon. These equations are derived under the assumption that the non-viscous fluid is incompressible and rotation free, and that the fluid velocity components may be expressed in the form of the power series expansions with respect to the water depth. This procedure makes it possible to transform the original two-dimensional problem into a one-dimensional one, in which all unknown variables depend on time and a horizontal coordinate. The partial differential equations derived correspond to the conservation of mass and momentum. The solution of these equations is constructed by the finite difference method and an approximate discrete integration in the time domain. In order to estimate the accuracy of this formulation, theoretical results obtained for a specific problem were compared with experimental measurements carried out in a laboratory flume. The comparison shows that the proposed theoretical formulation is an accurate description of long waves propagating in water of variable depth. |
| attributes | [reviewed] [scientific] |
| language | en |
| ATTRIBUTE | VALUE |
|---|---|
| type | A |
| database id | 8066 |
| title | Application of SEM to analysis of permeability coefficient of cohesive soils |
| authors | Tomasz Kozłowski, Katarzyna Kurpias-Warianek, Łukasz Walaszczyk |
| pages | 47 — 64 |
| full text link | http://www.ibwpan.gda.pl/storage/app/media/ahem/ahem58str047.pdf |
| keywords | cohesive soils, permeability coefficient, SEM, NIA, cyclic freezing and thawing |
| affiliations | |
| abstracts | A series of experiments on samples of five clayey soils gave evidence that cyclic freezing and thawing significantly affects the permeability coefficient. An attempt to analyze these changes on base of the Scanning Electron Microscopy SEM photographs of microstructures has been made. A simplistic equation (Eq. 11) has been drawn, describing the permeability coefficient as a function of hydraulic radius and pore area. An approach to determine the permeability coefficient by Eq. (11) on base of SEM photographs, in which the pores were identified manually, yielded results comparable to the Falling Head Test (FHT). However, since the identification of pores in SEM photographs seems the critical point of the method, the Numerical Image Analysis (NIA) has been applied. The procedure of finding the optimum threshold Topt has been described, based on minimization of the deviation ∆ki, j, calculated as the absolute value of the difference kSEM, i, j and kFHT, j, i.e. the permeability coefficients determined by the SEM analysis and FHT, respectively. It has been proved that the optimum threshold values can be described as a function of image parameters, i.e. mean grey level Lmean and standard deviation σn. |
| attributes | [reviewed] [scientific] |
| language | en |
| ATTRIBUTE | VALUE |
|---|---|
| type | A |
| database id | 8067 |
| title | Spatially averaged log-law for flows over rough bed in zero- and non-zero-pressure gradient boundary layers |
| authors | Włodzimierz Czernuszenko |
| pages | 65 — 86 |
| full text link | http://www.ibwpan.gda.pl/storage/app/media/ahem/ahem58str065.pdf |
| keywords | open channel, log-law, non-uniform flow, rough flow, accelerating flows, decelerating flows |
| affiliations | |
| abstracts | Theoretical bases for building a logarithmic law for non-uniform flows over a large relative roughness are presented. In order to define the equivalent velocity distribution and to smooth out 3D flow irregularities, a special spatial averaging operation is defined. Basic equations are spatially averaged and double-averaged momentum equations for primary component velocity are derived for uniform flow over a gravel bed as well as for non-uniform flows. A new hypothesis is proposed, and some assumptions are introduced to solve these momentum equations. This results in a new version of the logarithmic velocity distribution (log law). To define this distribution, a full reconstruction of Nikuradse’s graph for flows over an irregular gravel riverbed is considered. It is based on very precise measurements of velocity and other hydraulic parameters. In the case of non-uniform flows, the logarithmic velocity profile appears also in accelerating flows in a gravel bed channel, but the friction velocity should be re-defined according to Eq. (24). The same applies to decelerating flow with a positive pressure gradient, but only if the gravitational force exceeds the pressure gradient. For accelerating flows, the additive constant BP depends on the pressure gradient, and its values grow with a growing pressure gradient. |
| attributes | [reviewed] [scientific] |
| language | en |