In this paper, numerical results of modeling of acoustic waves propagation are presented. For calculation of the acoustic fluctuations, a solution of the full non-linear Euler equation is used. The Euler equations are solved with the use of a numerical scheme of third-order accuracy in space and time. The paper shows a validation process of the described method. This method is suitable also for an aerodynamic noise assessment on the basis of unsteady mean flow field data obtained from a CFD calculations. In such case this method is called a hybrid CFD/CAA method. The proposed method is numerically decoupled with CFD solution, therefore the information about the mean unsteady flow field can be obtained using an arbitrary CFD method (solver). The accuracy of the acoustic field assessment depends on the quality of the CFD solutions. This decomposition reduces considerably the computational cost in comparison with direct noise calculations.
The presented Euler acoustic postprocessor (EAP) has been used for modeling of the acoustic waves propagation in a cavity and in the flow field around a cylinder and an aerodynamic profile.
This paper addresses the issue of language and belonging in the transnational context of migration. It draws on two research projects with first-generation children of Polish labour migrants in Scotland. The paper examines the role that language plays in fostering multiple ways of being and belonging, and in understanding how children make sense of their identity. It suggests that language should take a more central place in debates about cultural connectivity and transnational migration. Findings point to the need for a more holistic approach to supporting migrant children, including the explicit recognition of family cultural and language capital in the host society.
Geometry of the fluid container plays a key role in the shape of acoustic streaming patterns. Inadvertent vortices can be troublesome in some cases, but if treated properly, the problem turns into a very useful parameter in acoustic tweezing or micromixing applications. In this paper, the effects of sinusoidal boundaries of a microchannel on acoustic streaming patterns are studied. The results show that while top and bottom sinusoidal walls are vertically actuated at the resonance frequency of basic hypothetical rectangular microchannel, some repetitive acoustic streaming patterns are recognised in classifiable cases. Such patterns can never be produced in the rectangular geometry with flat boundaries. Relations between geometrical parameters and emerging acoustic streaming patterns lead us to propose formulas in order to predict more cases. Such results and formulations were not trivial at a glance.