Nico Jurtz

• Dr.-Ing.
• CFD Development Engineer at BSH Hausgeräte GmbH

Zusammenfassung Zur Reduzierung der NO x ‐Emissionen bei der Verbrennung im Gasmotor hat sich die selektive katalytische Reaktion mit Ammoniak durchgesetzt. Insbesondere für kleine Motoren stellt die Katalysatorapplikation und die Einbringung des Reduktionsmittels eine große Herausforderung dar. In dieser Arbeit werden experimentell die Alterungser...

Fluidized particulate systems can be well described by coupling the discrete element method (DEM) with computational fluid dynamics (CFD). However, the simulations are computationally very demanding. The computational demand is drastically reduced by applying the coarse grain (CG) approach, where several particles are summarized into larger grains....

The mixing performance and power consumption for four dual‐impeller configurations in a stirred tank are studied using the mean age theory (MAT) approach, the fully transient techniques (FTT), and experiments. A novel method is developed based on the scaled mean age probability distribution curve, allowing the MAT method to be applied to multi‐impe...

Three numerical methods to determine the mixing time in stirred tanks are investigated using Computational Fluid Dynamics (CFD). In a cylindrical tank, the mixing performances of a Rushton turbine (RT) and a pitched blade turbine (PBT) are investigated, using transient methods, i.e., the Unfrozen Flow Field (UFF) and the Frozen Flow Field (FFF) met...

Slender fixed-bed reactors are widely used in the chemical industry, especially in the field of heterogeneous catalysis. This reactor type is characterized by strong heterogeneities in bed morphology that cause local flow phenomena to become dominant, which affect the heat and mass transport significantly. The design of these devices is therefore a...

The description of the mixing characteristics is of fundamental interest for modeling mass transport in fixed‐bed reactors. A method based on Lagrangian parcel tracking is presented to determine the axial dispersion coefficient in the mechanical dispersion regime from particle‐resolved computational fluid dynamics (CFD) results. The impact of fluid...

Process intensification of catalytic fixed-bed reactors is of vital interest and can be conducted on different length scales, ranging from the molecular scale to the pellet scale to the plant scale. Particle-resolved computational fluid dynamics (CFD) is used to characterize different reactor designs regarding optimized heat transport characteristi...

Fixed bed reactors are widely used in the chemical, nuclear and process industry. Due to the solid particle arrangement and its resulting non-homogeneous radial void fraction distribution, the heat transfer of this reactor type is inhibited, especially for fixed bed reactors with a small tube to particle diameter ratio. This work shows that, based...

Slender packed beds are widely used in the chemical and process industry for heterogeneous catalytic reactions in tube-bundle reactors. Under safety and reaction engineering aspects, good radial heat transfer is of outstanding importance. However, because of local wall effects, the radial heat transport in the vicinity of the reactor wall is hinder...

Interdisciplinary approach to designing with phase change materials (PCMs) can widen the range of architectural elements for passive cooling of buildings. Due to the complex nature and the dynamic character of phase-changing processes, the analysis and prediction of the thermal performance of PCM elements can be challenging to implement in architec...

Session: Modeling Tools and Techniques for Process R&D I 2:10 PM - 2:30 PM (CDT) ************************************************************************* Co-Authors: Nico Jurtz, Technical University Berlin; Ravindra Aglave, Siemens PLM Software; Thomas Eppinger, Siemens PLM Software; Matthias Kraume, Technische Universität Berlin ****************...

The accuracy of coarse‐grained discrete element method (CGDEM) relies on appropriate scaling rules for contact and fluid‐particle interaction forces. For fluidized bed applications, different scaling rules are used and compared with DEM results. The results indicated that in terms of averaged values as mean particle position and voidage profile, th...

Catalytic fixed‐bed reactors with a low tube‐to‐particle diameter ratio are widely used in industrial applications. The heterogeneous packing morphology in this reactor type causes local flow phenomena that significantly affect the reactor performance. Particle‐resolved computational fluid dynamics has become a predictive numerical method to analyz...

The impact of different silica nanoparticles on rheology, interfacial tension and drop size distributions in liquid‐liquid systems is determined experimentally. The particles vary in wettability and specific surface area. In contrast to commonly used high‐energy devices for Pickering emulsion preparation, low energy input by stirring allows to quan...

There have been an increasing number of publications on flow chemistry applications of compact NMR. Despite this, there is so far no comprehensive workflow for the technical design of flow cells. Here, we present an approach that is suitable for the design of an NMR flow cell with an integrated static mixing unit. This design moves the mixing of re...

The impact of the static friction coefficient, the initial particle orientation, and the particle height‐to‐diameter ratio on the bed voidage of random packings with a low tube‐to‐particle diameter ratio is investigated for spherical and cylindrical particles using the discrete element method. Based on the numerical results a correlation is propose...

The experimental accessibility of disperse systems often is a critical factor when it comes to the development of modeling approaches that intend to converge towards an exact solution. Often, integral or pseudo‐homogeneous values are used to reduce the complexity of the system, but a detailed single particle or interface analysis is crucial to unde...

In 2006, Dixon et al. published the comprehensive review article entitled “Packed tubular reactor modeling and catalyst design using computational fluid dynamics.” More than one decade later, many researchers have contributed to novel insights, as well as a deeper understanding of the topic. Likewise, complexity has grown and new issues have arisen...

Transport processes in packed reactors have transient behavior (e.g., adsorption, desorption, or Chemical-Looping) [1]. For reactors with a low tube-to-particle diameter ratio, particle resolved CFD simulations have been used extensively in the last years to accurately predict the steady-state conditions (see [2], [3] and [4]). Simplified models re...

No abstract is available for this article.

Fixed-bed reactors with a small tube-to-particle diameter ratio are typically used for highly exothermic or endothermic reactions. Flow, temperature and species distribution as well as the reaction rates are affected by the effect of the confining wall. In this study we have investigated numerically a spatially resolved fixed-bed including a detail...

This paper details experiments and CFD modeling for membrane separation process for both gas and liquid separation processes. http://www3.aiche.org/proceedings/Abstract.aspx?PaperID=401266

Packed bed reactors are widely used in the chemical and process industry amongst others for highly exothermic or endothermic catalytic surface reactions. Such reactors are characterized by a small tube to particle diameter ratio D/d to ensure a safe thermal management. For the design of such apparatuses the well-known correlations for packed bed re...

Introduction Packed bed reactors are widely used in the chemical and process industry amongst others for catalytic surface reactions. The model based design of such reactors is often done with simplifications, e.g. plug flow and an equally distributed porosity over the whole packed bed which are not valid for reactors with a small tube to particl...