Since 2011, Schwartze id.vt and Averem Verfahrenstechnik GmbH have been cooperating in various projects solving process engineering tasks. The focus of both companies is a comprehensive examination of questions for conceptual and basic engineering. Various solution techniques can be applied depending on the type of project: mass and energy balancing, fluid flow analysis and CFD simulations.
Due to quite profound experience in the field of CFD simulations by Schwartze id.vt as well as within the team of Averem Verfahrenstechnik there has always been a discussion on how CFD could be included in the companies’ software tool box. But prices for common CFD software have been so high that it would only be profitable when using it full-time. When SimScale started to offer its web-based CFD packages, CFD simulations were possible to offer as a complementary service. One of the first projects where SimScale had been used was the air flow around vertical tubes, covered with an absorption liquid.
Because of production limitations, there was a distance of at least 4 mm between the wall of the filter housing and the tubes. No question there would be shortcut flow. However, the questions to solve were how much of the air entering the filter escapes through the border area and are there some tubes where the fluid does not pass, i.e. a quantitative estimate in order to evaluate whether the levels of shortcut flow were acceptable or not. In the case of too much shortcut flow, device modifications should be investigated; CFD simulations were the perfect tool to solve these questions.
A CAD model for the tubes and the housing was created and uploaded in SimScale. The automated mesh generation for internal flow resulted in a mesh that could have directly been used for the flow simulations. All required boundary conditions and models were set and the simulation was performed on 8 nodes. The desired accuracy for the numerical solution was reached after about one hour. The flow field was analysed in the post-processor ParaView.
The CFD simulations have been validated by manual estimation of mass flow through the border area and a comparison to empirical fluid flow through filter tubes.
Investigating velocities and streamlines of the flow field showed the need for device modifications at the filter housing. A suggestion was to put metal sheets at the wall in order to break the border flow. The metal sheets were included in the geometry and CFD simulations have been performed. The new concept showed a more uniform flow field and an acceptable level of shortcut flow which overall results in higher performance values of the filter.