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Heschl, Christian
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Official Name
Heschl, Christian
Alternative Name
Heschl, C
Main Affiliation
Akademische Titel
Prof.(FH) Dipl.-Ing. (FH) Dr.
Email
christian.heschl@fh-burgenland.at
Scopus Author ID
50161591800
Status
staff
Research Outputs
Now showing 1 - 6 of 6
- PublicationEvaluation of eddy viscosity turbulence models to predict convective heat transfer(2012-12)
; 116 1 - PublicationMicron particle deposition in the nasal cavity using the v2–f modelCommercial CFD codes are commonly used to simulate models that involve complicated geometries such as the human nasal cavity. This means that the user has to work within the limitations of the available models of the CFD code. One such issue is the turbulent dispersion of particles in the Lagrangian reference, namely the Discrete Random Walk (DRW) model which overpredicts the deposition of smaller inertial particles, due to its inherent isotropic treatment of the normal to the wall fluctuation, v′ , in the near wall region. DNS data for channel flows has been used to create a function that reduces the turbulent kinetic energy (TKE) to match the v′ profile which has delivered improved particle deposition efficiency results. This paper presents an alternative approach to reduce the TKE to match v′ , by directly taking the profile from the v2–f turbulence model. The approach is validated against experimental pipe flow for a 90° bend and then applied to particle dispersion in a human nasal cavity using Ansys-Fluent which showed improved results compared to no modification.
137 1Scopus© Citations 34 - PublicationNonlinear eddy viscosity modeling and experimental study of jet spreading ratesIndoor airflow pattern is strongly influenced by turbulent shear and turbulent normal stresses that are responsible for entrainment effects and turbulence-driven secondary motion. Therefore, an accurate prediction of room airflows requires reliable modeling of these turbulent quantities. The most widely used turbulence models include RANS-based models that provide quick solutions but are known to fail in turbulent free shear and wall-affected flows. In order to cope with this deficiency, this study presents a nonlinear k-ε turbulence model and evaluates it along with linear k-ε models for an indoor isothermal linear diffuser jet flow measured in two model rooms using PIV. The results show that the flow contains a free jet near the inlet region and a wall-affected region downstream where the jet is pushed toward the ceiling by entrainment through the well-known Coanda effect. The CFD results show that an accurate prediction of the entrainment process is very important and that the nonlinear eddy viscosity model is able to predict the turbulence-driven secondary motions. Furthermore, turbulence models that are calibrated for high Reynolds free shear layer flows were not able to reproduce the measured velocity distributions, and it is suggested that the model constants of turbulence models should be adjusted before they are used for room airflow simulations.
129 1Scopus© Citations 10 - PublicationComputation of the temperature distribution in biomass boilers with reciprocating grate furnaces(2015-12)
; ; ; Tu, Jiyuan148 1