On the development of direct numerical simulations for falling films
- Autores: Nicolás Valle Marchante
- Directores de la Tesis: Jesús Castro González (dir. tes.), Assensi Oliva Llena (codir. tes.)
- Lectura: En la Universitat Politècnica de Catalunya (UPC) ( España ) en 2021
- Idioma: español
- Materias:
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- Resumen
Multiphase flows present a rich variety of physical instabilities, which may turn into a set of interesting techonological features. In the particular case of vertical fallings films, these features provide with short residence times, good heat transfer coefficients and low pressure drop, which make them good candidates for the heat and mass transfer demands of absorption chillers, amid many other thermal and chemical applications.
The adoption of a discrete vector calculus approach for the numerical treatment of such flows present with two synergistic advantages: on the one side, the deployment of numerical methods into massive supercomputing systems is favourished while, on the the other hand, the mathematical properties of the resulting algorithms can be conveniently revealed.
Similarly to the symmtery-preserving ideas in place for the Direct Numerical Simulation of single phase turbulent flows, and equipped with the aforementioned mathematical machinery, a novel physics-compatible discretization for the numerical computation of multiphase flows is presented which, similarly to its single phase counterpart, preserves energy at the discrete level.
The new method introduces the first variation of area in the context of a the Conservative Level Set method to match the kinetic energy contribution due to the capillary forces with the potential energy variation due to the interface deformation. This requires for the reormulation of the high ressolution scheme used for the transport of the marker function from an algebraic perspective, which ultimatelly yields to the design of a novel curvature interpolator. In addition, the adoption of a consistent mass and momentum discretization is presented in terms of the aforementioned algebraic approach, resulting in the anounced energy-preserving level set method.
