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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 - 10 of 36
- Publication
134 1 - PublicationImproving predictions of heat transfer in indoor environments with eddy viscosity turbulence modelsHeat transfer modelling in indoor environments requires an accurate prediction of the convective heat transfer phenomenon. Because of the lower computational cost and numerical stability, eddy viscosity turbulence models are often used. These models allow modification to turbulent Prandtl number, and near wall correction which influences stagnation points, entrainment, and velocity and time scales. A modified v 2–f model was made to correct the entrainment behaviour in the near wall and at the stagnation point. This new model was evaluated on six cases involving free and forced convection and room airflow scenarios and compared with the standard k–ε, and k–ω–SST models. The results showed that the modification to the v 2–f model provided better predictions of the buoyant heat transfer flows while the standard k–ε failed to reproduce and underestimate the convective heat transfer. The k–ω–SST model was able to predict the flow field well only for a 2D square cavity room, and 3D partitioned room case, while it was poor for the other four cases.
156 1Scopus© Citations 2 - Publication
156 1 - PublicationEvaluation of eddy viscosity turbulence models to predict convective heat transfer(2012-12)
; ;Inthavong, KiaoTu, JiyuanWithin the CFD-optimization process of thermal energy conversion systems an accurate prediction of the convective heat transfer is required. Because of the lower computational effort and the numerical stability, eddy viscosity turbulence models are often used. Besides the different velocity and time scales the eddy viscosity concept offers a lot of modifications such as variable turbulent Prandtl number, stagnation point, entrainment and near wall correction.116 1 - PublicationTowards non-invasive temperature measurements in HVAC: A characterization and correction approach(IEEE, 2019-06)
; ; ; ; ;Sauter, ThiloTreytl, AlbertThe existing building stock within the European Union is responsible for a considerably huge amount of the total energy consumed. This has prompted legislative actions that focus on increasing the efficiency of Heating, Ventilation and Air Conditioning facilities by employing building automation and electronic monitoring systems. The fluid flow temperature in the hydraulic grid of a building is therefore an essential parameter to be measured, where clamp-on temperature sensors are often applied due to their simple and cost-effective installation. As the plumbing industry heads towards non-metal pipe materials with low thermal conductivity, the applicability of non- invasive measurement procedures diminishes. In this context, a characterization approach of non-invasive temperature measurements that is linked to a thermal resistance model is experimentally validated. Based on that, a correction algorithm to reduce the deviation between measured surface and the fluid flow temperature for steady state conditions is derived and tested. The presented approach provides sufficient characterization and correction performance, albeit several limitations have to be taken into consideration.423 1Scopus© Citations 1 - Publication
20 2Scopus© Citations 1 - PublicationA New Algebraic Reynolds Stress Turbulence Model for Prediction of Wall-Affected Three Dimensional Room AirflowsIn the past various experimental investigations about room airflows were published. But most investiagtions are limited regarding measurements positions (restricted gflow patttern) and the availability of turbulent quantities (Reynolds-Stresses, entrainment, macroscopic instabilities etc.) based on the avaiable experimental data a targeted improvement of turbulence models is difficult. Therefore a complex three dimensional room airflow situation was investigatedwith three-dimensional Particle Image Velocmetry. Detailed informatiom of the floww, the Reynolds-stress distribution and the entertainment are presented. Based on the experimental results the behaviour of RANS-based turbulence models in predicting roomairflow is discussed. In this context, it is shown that intensive anisotropic Reynolds stresses near the wall arise and influences the airflow pattern. For this reason a new algebraic Reynolds stress turbulence model - which can in princible reproduce the turbulence anisotropic behaviour- is proposed. Compared with the linear eddy viscoity turbulence models the new nonlinear model agrees clearly better with the presented experimental findings.
128 1 - PublicationInstationäre Simulation der thermischen Behaglichkeitsparameter im Sommerfall mit CFD(2011)
; ; ; ;Nikolics, M.Velikovsky, R.130 2