Computational fluid mechanics based on the finite element method has been developed so far following two distinct approaches (a) using a stream function, or stream functlon-vortlcity formulation [1,2], and (b) using a primitive variables formulation [3,4,5]. Within the first approach a stream function is defined such that the continuity equation is identically satisfied and the momentum equatio...

the paper presents the results of an investigation on the acoustic performance of vertical profile parallel barriers with quadratic residue diffuser tops and faces. a 2d boundary element method (bem) was used to predict the barrier insertion loss. the results of rigid and with absorptive coverage were also calculated for comparisons. using qrd on the top surface and faces of all vertical profil...

1 EXECUTIVE SUMMARY In a low frequency analysis of vibration in a built-up structure, the eigen frequencies and the corresponding eigenmodes help the understanding of how and why the structure behaves as it does. These eigen solutions are also useful in calculations of forced response by modal super-position procedures. However, as frequency increases there are more and more modes with increasi...

and this problem can be solved analytically: u (x) = x − sinhx/sinh1. The purpose of starting with this problem is to demonstrate the fundamental concepts and pitfalls in FEM in a situation where we know the correct answer, so that we will know where our approximation is good and where it is poor. In cases of practical interest we will look at ODEs and PDEs that are too complex to be solved ana...

Finite element methods are based on the variational formulation of partial differential equations which only need to compute the gradient of a function. Although unknowns are still associated to nodes, the function composed by piece-wise polynomials on each element and thus the gradient can be computed element-wise. Finite element spaces can thus be constructed on general triangulations and thi...