Chair of Fluid Dynamics

The team develops and tests methods for the simulation and optimization of reactive flows and flames in installations such as heavy-duty gas turbines, nanoparticle synthesis reactors, piston engines or biomass- and pulverised coal furnaces. Our methods allow for shortened development times to further reduce costs. Our research helps to develop cost-effective, flexible and safe systems which emit fewer pollutants.

The complex processes in synthesis reactors and combustors require a detailed numerical characterisation of reaction and transport processes. Their simulation provides insights into areas, which are inaccessible to experiments, enables the investigation and comprehension of isolated subprocesses, and their interactions, and helps to bridge the gap between lab and industrial scale. For this purpose we develop and implement numerical models and methods which are necessary to describe and simulate turbulent combustion of multiphase flows as well as reaction kinetics.

Our work is financed by the state of North Rhine-Westphalia, the German Research Foundation (DFG), the Federal Ministry of Economics and Technology (BMWi), the Alliance for industrial research (AiF), national and international supercomputing centres as well as multiple private companies.

At the University of Duisburg-Essen, our group is closely linked with other groups at CeNIDE (Center for Nano-Integration Duisburg-Essen), CER.UDE (Center for Energy Research) and CCSS (Center for Computational Sciences and Simulation). As a menber of the IVG, we provide detailed simulation results and utilize data from the experiments of the other groups, which are essential for us.

The study at the chair imparts competences in the fields of flow simulation, in the description of reacting flows and in turbulence modeling.

NEWS

Publ Combtheorymodel Inanc 20210721
 

27.07.2021

Publication accepted in Combustion Theory and Modelling

In this collaborative work with Newcastle University, the validity of the famous flame efficiency function models for stratified flames are tested. 


11.06.2021 Publication accepted in Flow Turbulence and Combustion

In a joint study with the Stanford University an investigation torwards the suitability of the information entropy as a quality measure was performed. Canonical cases of fluiddynamics and chaos-theory were analyzed and a dependence between the simulation quality and information entropy has been observed. Well and poorly resolved simulations were performed, and have been compared with DNS data. While several established quality measures failed to assess the simulation quality correctly, the entropy was able to distinguish between the poor and well resolved calculations. Link

26.02.2021 Publication accepted in Energy & Fuels

A hydrogen-piloted pulverized coal flame is investigated using a flamelet/progress variable approach via massively parallel LES. A method is presented that accounts for suction probing effects on the scalar field measurements and significantly improves the agreement between experiment and simulation. This work is a collaboration with the TU Darmstadt and the University of Stuttgart. Link

15.02.2021 Publication accepted in Energy & Fuels

A collaborative work in the framework of DFG-FOR2284 project. The thermal decomposition of ethylsilane (H3SiC2H5, EtSiH3) is investigated behind reflected shock waves and the gas composition is analyzed. A kinetics mechanism accounting for the gas-phase chemistry of EtSiH3 is developed, which consists of 24 Si-containing species, 31 reactions of Si-containing species, and a set of new thermochemical data. The experimental data is reproduced very well by simulations based on the mechanism of this work and is in very good agreement with literature values. It is shown that EtSiH3 is a promising precursor for the synthesis of SiC nanoparticles. Link

18.01.2021 Publication accepted in Energy & Fuels

A comprehensive Euler-Lagrange framework for pulverized coal combustion using detailed multi-step heterogeneous kinetics is presented. 3D carrier-phase DNS have been performed for a turbulent mixing layer. The data is compared to simpler pyrolysis models. A new devolatilization model approach suitable for fitting bimodal volatile release rates is proposed. This work is a collaboration of the University of Stuttgart, TU Darmstadt and University of Duisburg-Essen. Link

06.01.2021 Publication accepted in Computer and Fluids

The behaviour of bounded passive scalars with respect to different subgrid-models in a-posterori LES is investigated in a joint study together with the Bundeswehr University Munich. DNS and LES calculations using known and new subgrid-models have been performed for a turbulent free jet. The influence of cross-combination of different models as well as the choice of numerical discretization for the subgrid-fluxes on the boundedness of the transported scalars is analyzed.

22.12.2020 Publication in Optics Express

A novel application of tomographic imaging using multi-simultaneous measurements (TIMes) for flame emission reconstructions. Link

08.12.2020


Hänel

We mourn the loss of Dieter Hänel

On November 29, 2020, we lost
our colleague and friend

Prof. Dr.-Ing. Dieter Hänel
* 1942        + 2020

Dieter Hänel was professor at the University of Duisburg-Essen from 1991 until 2008. His scientific work was dedicated to numerical fluid mechanics. His ideas were instrumental in the development of solution methods for compressible flows. His influence was even greater on the development of the Lattice-Boltz­mann methods, which he actively developed until his retirement. He dedicated the textbook "Molecular Gas Dynamics" to kinetic gas theory. His work as a university teacher and doctoral supervisor, his way of awakening curiosity and then allowing it to flourish in freedom, has inspired numerous students to pursue a career in science and an academic career as researcher and teacher.

Dieter Hänel will remain in our memories.
Our deepest sympathies go to his family.

Prof. Dr.-Ing Andreas Kempf, Prof. Dr. Khadijeh Mohri, Dr. Irenäus Wlokas, colleagues and all members of staff at the IVG.
 

28.09.2020 Publication accepted in Fuel

A pseudo-DNS of an auto-igniting pulsed jet is presented. The simulation used the HPC Hazel Hen in Stuttgart, where the computational-cost is 40 million CPUh. 

17.07.2020 Publication accepted in Proceedings of the Combustion Institute

A collaborative work with the University of Stanford was accepted in the Proceedings of the Combustion Institute. This paper presents quantum-chemical calculations and isodesmic reaction schemes for the determination of temperature-dependent heat of formation, entropy, and heat capacity of Si–C–H radicals and molecules, from which group additivity values (GAVs) were obtained from combinatorial considerations.

17.07.2020 Publication accepted in Proceedings of the Combustion Institute

A collaborative work as a combination of the simulation and experiment was accepted in the Proceedings of the Combustion Institute. This study investigates the chemical reaction mechanism of tetramethylsilane in a series of H2 /O2 /Ar low-pressure (p=30 mbar) flames from fuel-lean to slightly fuel-rich flame conditions (φ=0.8, 1.0 and 1.2). The experimental data are compared to simulations using a recently published reaction mechanism.

09.06.20 Publication accepted in Proceedings of the Combustion Institute

An efficient method to correct the overestimated species predictions in thickened flame models is presented. This work is a collaboration between the University Duisburg-Essen and the Université Paris-Saclay.

08.06.2020 Publication accepted in Combustion Science and Technology

In this work, a lean premixed high pressure jet flame is investigated by LES. Simulations using different combustion models are compared with the experimental data and the pollutant formation of carbon monoxide and nitrogen oxide, as well as the stabilization of the flame is analyzed.