Hochschule Karlsruhe Hochschule Karlsruhe - University of Applied Sciences
Hochschule Karlsruhe Hochschule Karlsruhe - University of Applied Sciences

Institute of Digital Materials Science

Microstructure - Diffusion

Modelling of heat transport in porous structures under the influence of flows, among other things.

The research activities of the group "Microstructure - Diffusion", of Dr. rer. nat. Anastasia August, include the modelling of heat transport in porous structures, among others under the influence of flows. The aim is to improve the efficiency of heat exchangers, heat collectors and heat stores depending on the microstructure and material properties. Phase transformation processes of the fluid medium are taken into account when modelling the process sequences. The research group develops optimal structures of the porous materials involved, for example the structure of a metal foam.

(Foto: Dr. Marco Berghoff)

Most important research projects

Metal foams

Metal foams are materials with excellent properties. They look like beer foams, only without beer and essentially without the partitions between the individual bubbles. Only where three or more bubbles meet is there still material. These so-called webs form an irregular, solid network that still largely possesses many of the properties of the basic material - metal: Thermal conductivity, stability and electrical conductivity. In addition, they offer much more: the lightness, the lower base material requirement and - most importantly - the large surface area compared to the volume. For example, heat can be exchanged with the air around the webs via this surface. This property, combined with the good thermal conductivity of metal, makes metal foams popular subjects of our research, within the framework of the KIT programme Energy Efficiency, Materials and Resources.

Link: http://www.emr.kit.edu/ 

Solar thermal

Solar energy can be absorbed particularly well by black objects. For example, the skin of a polar bear is black so that it can get as much energy as possible out of the sunlight at the North Pole. The white fur hairs that let the sunlight through serve to insulate its own body heat. Using this principle, heat collectors made of textile spacer fabric are being developed in the solar thermal project - together with our project partner, the Institute of Textile Technology and Process Engineering Denkendorf (→ www.uni-stuttgart.de/forschung/orp/inst_profile/we/itv.html). In addition to energy generation, their storage also plays a major role, of course. In the second project step, new storage systems are being tested: For example, small buckets the size of a thimble filled with paraffin, which are to be placed directly under the textile collector. Paraffin stores latent heat when it melts and releases it again when it solidifies. At CMS, we test different systems with the help of computer simulations and make suggestions for improving their geometry.

Porous water pipes

The most efficient possible use of energy resources is an important challenge for the future. In the material sciences, this results in the search for efficient, cheap and practical materials for heat conduction and storage. Metallic foams represent a promising approach to solving problems of energy transfer and storage, as they possess both the property of permeability to fluids and that of large surface area. This enables more efficient heating of fluids and other possible fillings. The aim here is to achieve the greatest possible heat transfer with the lowest possible pressure loss at the same time. These foams are first produced in computer simulations in which the material is tested for various conditions, such as changes in temperature or pressure, and the influence of different pore sizes. Then, with the help of a 3D printer, a model is produced for the investment casting of the optimal foam.
Metal foams are used, for example, in the design of water pipes that transfer their energy more efficiently to the water.

InSeL: Innovative Foam Structures for Efficient Lightweight Construction

The research project InSeL (Innovative Foam Structures for Efficient Lightweight Construction) is a research initiative for lightweight construction research in Baden-Württemberg, consisting of the association of various universities, non-university institutions and companies in which KIT's IAM is involved. It includes joint research, but also the knowledge communication of research results to companies as well as the networking of InSeL members to further research projects. The focus is on three aspects:

Innovation aspect:

As technology continues to advance, porous structures are very much in demand as materials, but their development poses some challenges, such as the development of composites.

Economic aspect:

The InSeL project aims to enable the economic exploitation of porous materials that have not been sufficiently harnessed to date. This will increase the competitiveness of medium-sized companies in particular.

Communication aspect:

This aspect includes knowledge communication to companies. The interdisciplinary approach is also intended to strengthen communication among researchers.

In addition, the interdisciplinary approach is intended to strengthen communication among researchers.

Our sub-project:

Here at CMS, we are participating in this project through computer simulations in the field of polymer foams, which serve as preforms in the casting of particularly fine-pored and monodisperse metal foams.

Link: https://www.hs-pforzheim.de/insel

Groupleader

Dr. rer. nat. Anastasia August
anastasia.augustspam prevention@h-ka.de

Quick Access

Groupmembers

Popular Science Lectures by Dr Anastasia August