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.

On Two Mechanisms of Sound Generation in Turbulent Jets

Abstract: Features of the processes of sound generation in turbulent jet flows are analyzed. Two possible processes are considered, namely, noise of dissipating turbulence and noise generated by largescale turbulent-flow perturbations which accompany propagation of turbulent jets. The data of the theoretical and experimental investigations of statistical turbulence theory are used to estimate the first of the above-mentioned effects. The data of computational experiments are used to analyze the process of sound generation by large-scale perturbations. In these numerical experiments time-dependent subsonic turbulent jet flows were directly calculated using the LES technology and the experimental data. It is shown that the noise of large-scale perturbations can be satisfactorily reproduced by the numerical simulation and its properties correspond to the experiments on studying sound generation in jets; the contribution of noise of dissipating turbulence to the total jet noise seems to be insignificant.

Short communication. Effect of forage source (grazing vs. silage) on conjugated linoleic acid content in milk fat of Holstein-Friesian dairy cows from Galicia (NW Spain)

Abstract: The aim of this study was to investigate the effect of different feeding proportions of forage ―grazing vs. silage― on milk fatty acids (FA) profile and conjugated linoleic acid (CLA) content of autumn calving Holstein-Friesian cows (n = 61) at CIAM (Galicia, NW Spain). Three treatments (S, 100% silage; G/S, 50% grazing + 50% silage; G, 100% grazing) were set and milk FA profile of dairy cows was determined by gas chromatography-mass spectrometry. The G group showed a decrease in short ( p < 0.05) and medium chain FA ( p < 0.001), with an increase in long chain FA ( p < 0.001) in comparison to the G/S and S groups, which showed the lowest levels ( p < 0.001) of mono- and polyunsaturated FA. The CLA content in milk fat increased ( p < 0.001) linearly in relation to the increased proportion of fresh grass in the diet of dairy cows from 0.49 and 0.82 to 1.14 g/100 g FA for the treatments S, G/S and G, respectively. During spring and summer, the levels of CLA were three times higher ( p < 0.001, +0.76 g/100 g FA) in milk from dairy cows at the G group than in cows at the S group and twice higher ( p < 0.001, +0.40 g/100 g FA) than in cows at the G/S group. High proportion of grass in the diet of cows increased CLA content, with the highest levels of unsaturated FA and the lowest levels of saturated FA, increasing the added value of milk on grazing systems using available farm resources.

Efecto de la fecha de corte y del uso de aditivos en la composición química y calidad fermentativa de ensilado de girasol

Abstract: El objetivo fue evaluar fechas de corte y del uso de aditivos sobre la calidad del ensilado de la planta entera de girasol. La variedad forrajera (Rumbosol-91) se cosecho en las semanas 1, 3 y 5 post-floracion (F1, F2 y F3, respectivamente) y tratada con los siguientes aditivos: 1) 1.5 × 105 ufc de inoculante g -1 de forraje, a base de bacterias lacticas homofermentativas Enterococcus faecium , Pediococcus pentosaceus y Lactobacillus plantarum (INOC), 2) 3 ml kg -1 de forraje de una solucion al 85% de acido formico (FORM) y 3) sin aditivo (Testigo); siguiendo un diseno factorial 3x3 con cinco repeticiones. La produccion de efluente y las perdidas totales de materia seca (MS) se redujeron, desde 282 y 134 g kg -1 en F+1 hasta 96 y 87 g kg -1 en F+5 como resultado del alto contenido de humedad del forraje proxima a la floracion. El analisis NIRS de las muestras de ensilaje mostro que los contenidos de proteina, fibra y digestibilidad descendian significativamente con la madurez de la planta; la rapida acumulacion de aceite en la MS hizo que la concentracion energetica fuese superior en el estado fenologico mas avanzado. La calidad fermentativa de los ensilajes fue satisfactoria, independientemente del momento de corte y del uso de aditivo. Se concluye que es preferible el corte de la planta a las cinco semanas post-floracion, donde se espera una fermentacion aceptable sin necesidad de conservantes.

4convective heat transfer in the boundary layer flow of a maxwell fluid over a flat plate using an approximation technique in the presence of pressure gradient

Abstract: In this study, the effect of pressure gradient have been included for heat transfer in the boundary layer flow of Maxwell fluid over a flat plate.The solution of the problem is obtained with an application of algorithms of Adams Method (AM) and Gear Method (GM) with Homotopy Perturbation Method (HPM) as an approximation technique. This technique shows the outcomes of pressure gradient (m), Deborah number (β) and Prandtl number (Pr) in the boundary layer flow on temperature and velocity profiles, also the momentum and thermal boundary layer thickness and discussed. To obtain this objective, the momentum and energy equations of Maxwell are solved. The outcomes of HPM in the absence of relaxation time (λ) or Deborah number (β) and pressure gradient (m) (i.e. λ = β = m = 0) at Prandtl number Pr = 1 are in closed relation with the numerical results having the value of η∞ is around 5. Also it is found that the system is convergent, as a whole momentum and thermal boundary layer thicknesses becomes thinner and thinner. Importantly, some cooling effects of the Maxwell fluid over a flat plate for energy profile have been observed.

Exact solutions and lattice Boltzmann method modelling for shallow water equations

Abstract: In this study, lattice Boltzmann Method (LBM) is applied for shallow water flows problem in order to handle two dimensional flows. The LBM and its implementation in solving Shallow Water Equation (SWE)for physically significant nonlinear partial differential equations were also analysed.An analytical solution of steady and two dimensional SWE was derived from a cubic algebraic form of SWE, and obtained the analytical solution of unsteady and two-dimensional SWE from sub inertial and super inertial frequency quadratic algebraic form of SWE. The numerical solution of the two dimensional SWE was generated by applying the LBM. The LBM numerical result of SWE was then compared graphically with the SWE result obtained via the finite difference method (FDM). Our findings revealed that the simulation via LBM is more stable than FDM in the microscopic sense. AMS subject classification: