טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
M.Sc Thesis
M.Sc StudentTsarfis Igal
SubjectAssessment of Immersed Boundary Methods for Large Eddy
Simulations of Thermal-Hydraulic Turbulant Flows
DepartmentDepartment of Mechanical Engineering
Supervisor Professor Steven Howard Frankel
Full Thesis textFull thesis text - English Version


Abstract

Many physical phenomena in the real world are thermal-hydraulic flows. The focus of this work is thermo-hydraulic internal flows, which are common physical phenomena in many industrial applications, such as cooling piping, mixing tanks, and internal combustion engines. It is characterized with turbulent velocity and temperature field patterns that develop inside complex geometrical features. To adequately resolve the scalar mixing phenomenon, a high order numerical large eddy simulation solver is sought. This thesis assesses the use of immersed boundary methods to alleviate complexities emerge when high order numerical schemes have to be applied on industry level geometries of thermal flows applications.

To this end two high order numerics large eddy simulation academic codes where closely examined: the in-house wenoCFD solver that uses the weighted essentially non oscillatory high-order finite-differences scheme, and is based on a novel multi-block immersed boundary method that is capable of high-fidelity within complex geometries. And the Incompact3D solver that uses 6th order compact scheme, and has a general purpose immersed boundary method. Each of the solvers facilitates a different immersed boundary method approach.

The assessment and suitability of such approach to the flows at hand is showcased on case setups as the Vattenfall circular T-junction, passive scalar flow in a rectangular T-junction, the MATIS-H rod bundle, and the jet in a cross flow with passive scalar mixing. Results were compared with high quality experimental data, to a satisfactory level. Several insights, such as a work methodology, setting proper inlet, outlet, and adiabatic boundary conditions were gained during the work process, which could potentially improve and facilitate an industry level immersed boundary method code for thermal-hydraulic flows.