Congrès International d'Architecture Moderne

About: Congrès International d'Architecture Moderne is a based out in . It is known for research contribution in the topics: Boundary value problem & Jet (fluid). The organization has 393 authors who have published 403 publications receiving 4104 citations.

Modeling of propagation tsunami waves via lattice Boltzmann method

Abstract: We present an efficient implementation of the Lattice Boltzmann method (LBM) for the numerical simulation of the propagation of long ocean waves (e.g., tsunamis), based on the Nonlinear Shallow Water (NSW) wave equation. The Lattice Boltzmann Equation (LBE) method is an alternative numerical scheme for the description of incompressible hydrodynamics. The LBE method has potential to serve as an efficient solver for incompressible flows in complex geometries. In the present study, we propose nonlinear shallow water equations for irrotational surface waves for the case of complex bottom elevation. Nowadays shallow water equations have become the model of choice for operational tsunami modeling including the propagation zone estimation. Several test-cases are presented to highlight the added value of the new model. Some implications to tsunami wave modeling are also discussed. The numerical results are found to be in excellent agreement with theory.

Modeling turbulent boundary layer noise in the presence of sound absorbing devices

Abstract: The results of an experimental investigation of the natural noise of flow past two versions of sound absorbing devices are presented. On the basis of the known theoretical studies and the numerical calculations of the turbulent boundary layer over a rough surface a method for describing the noise of the above-mentioned devices is developed. The tests made using large eddy simulation show good agreement between the calculated and experimental data.

Thermal Plasticity: Cyclic Loading and Heating

Abstract: Cyclic durability of machine parts is related to material resistance against low cycle fatigue (LCF) under periodic (cyclic) loads and temperatures within the range from 10 to 104 cycles and above. This chapter deals with experimental and theoretical foundations of computational methods for estimating both isothermal and non-isothermal cyclic durability of engineering structures. Typical examples of material cyclic tests under varying loads and peculiarities of cyclic non-isothermal deformation diagrams are considered. In the last case, the heating and cooling half-cycles are not identical due to a difference in the occurrence of elastic and plastic zones. The role of material the so-called cyclic adaptability is emphasized. This phenomenon leads to cycle stabilization that ensures to a great extend of the long-term working capacity of machines. Stabilized cycles can be both simple and consisting of a set of half-cycles of different stress and temperature. It is shown that the number of cycles before LCF failure under arbitrary programs of periodic loading and heating can be calculated from Coffin–Manson’s curves by averaging plastic strain intensity magnitude over whole deformation process. Analysis of the factors influencing the thermal fatigue of machine parts coming from thermocyclic tests is presented along with efficient methods for calculating stresses and strains corresponding to synchronous non-isothermal cycles. The possibility for summation of cyclic damage is demonstrated for evaluating durability of variable cycles associated with unsteady loading and heating or unstable material parameters. It is shown that LCF can be evaluated using the normalized accumulated plastic strain related to its magnitude at failure. The absolute accumulated plastic strain (Odqvist’s parameter) at cyclic loading varies over a wide range and cannot be a criterion for cyclic damage accumulation and failure.

Diagnostics of metal samples using the results of experimental and theoretical study of positively charged microparticles formed upon sample destruction

Abstract: Destruction of bodies is accompanied by formation of both large and microscopic fragments. Numerous experiments on the rupture of different samples show that those fragments carry a positive electric charge. his phenomenon is of interest from the viewpoint of its potential application to contactless diagnostics of the early stage of destruction of the elements in various technical devices. However, the lack of understanding the nature of this phenomenon restricts the possibility of its practical applications. Experimental studies were carried out using an apparatus that allowed direct measurements of the total charge of the microparticles formed upon sample rupture and determination of their size and quantity. The results of rupture tests of duralumin and electrical steel showed that the size of microparticles is several tens of microns, the particle charge per particle is on the order of 10–14 C, and their amount can be estimated as the ratio of the cross-sectional area of the sample at the point of discontinuity to the square of the microparticle size. A model of charge formation on the microparticles is developed proceeding from the experimental data and current concept of the electron gas in metals. The model makes it possible to determine the charge of the microparticle using data on the particle size and mechanical and electrical properties of the material. Model estimates of the total charge of particles show order-of-magnitude agreement with the experimental data.

Comparación de procedimientos para elaborar colecciones nucleares en poblaciones españolas de raigrás inglés e italiano

Abstract: Durante dos anos se caracterizaron agromorfologicamente 74 poblaciones de raigras ingles y 42 de raigras italiano, pertenecientes a la coleccion de gramineas pratenses del Centro de Investigaciones Agrarias de Mabegondo (CIAM) Las variables significativas en el analisis de varianza se utilizaron en una clasificacion ascendente jerarquica mediante el metodo de Ward Sobre ambas colecciones de partida, se compararon diversas estrategias para crear dos colecciones nucleares ("core collection") Las estrategias empleadas incluyeron muestreos estratificados y aleatorios basados en la clasificacion jerarquica, en el indice de diversidad de Shannon-Weaver y en la maxima contribucion a la varianza en un analisis de componentes principales Ninguna de las colecciones nucleares creadas mostro diferencias en las medias y en las varianzas mediante el test de Wilcoxon Las colecciones seleccionadas en la estrategia de mayor contribucion a la varianza fueron las que presentaron un mayor porcentaje de retencion de los intervalos de variacion, por lo que dicha estrategia se considera la mas adecuada para el mantenimiento de la diversidad de las colecciones de partida