Catalyst Heat-Up Simulation
In the automotive and plant construction sector, catalyst systems are used to clean the exhaust gas from the engine. Commonly, the selective catalytic reduction (SCR) system is used to reduce the NOx emissions. For such purpose, the SCR catalyst substrate has to have a defined minimum temperature before the DeNOx reactant is injected (around 280 °C). The following tutorial gives details about the coupling of the fluid and solid region with an energy transfer between these regions.
Polluted air is a problem of many countries, especially in big cities or at landscapes in which the air exchange is small related to the geographical location. Thus, governments make laws such as TA-Luft, BImSchV in Germany, or stringent global regulation (world bank). Reducing the pollution of, e.g., engines, numerical methods can be used to perform optimization to the existing systems. Thus, the process can be designed more efficiently and effectively and, therefore, it is economically better.
In the computational fluid dynamic analysis, engineers are using a fixed rotation set-up for the moving mesh that includes the design of the turbine. However, if one is interested in a flow-induced rotation, the six degrees of freedom library in OpenFOAM® can be used to handle such analysis.
Arbitrary Rotating Inlet ACMI
The arbitrary coupled mesh interface (ACMI) condition is compelling if the usage of the boundary condition is well understood. The following training case builts an ACMI for a rotating inlet pipe, which is connected to a larger second pipe. The set-up is tricky and needs advanced techniques and applications for the correct ACMI generation.
The Magnus Effect
The investigation into different phenomena can be done easily with numerical analysis. Some of the most famous phenomena are already simulated by Holzmann CFD such as the Magnus Effect, the Taylor-Rayleigh instability or the Kelvin-Helmholtz instability. People who love soccer should be aware of the Magnus effect, as it is a very common phenomenon in this kind of sport. However, it is also necessary for golf, tennis, table-tennis and so on.
Arbitrary Coupled Mesh Interface
In engineering applications, it is common to have active parts which connect and disconnect. Using the arbitrary coupled mesh interface in OpenFOAM® allows one to use dynamic elements that connect and disconnect during the time. The usage of such boundary conditions and the correct set-up is the principal focus of this training case.
Arbitrary Rotating AMI
Dynamic meshes are state of the art for engineering processes. In many cases, the numerical analysis has to be adapted to the rotation because, e.g., the multi-reference-frame (MRF) assumption does not hold anymore. To investigate such a phenomenon, OpenFOAM® offers a mapping and interpolation boundary condition, namely the arbitrary mesh interface (AMI).
Pseudo-2D Adaptive Mesh Refinement
The adaptive mesh refinement (AMR) method is a common strategy for significant numerical cases, including phenomena that have to be reasonably resolved (mesh density). Using the AMR functionality, OpenFOAM® allows one to refine only the regions of interest. This training case models a pseudo-2D situation.
ACMI Boundary With Heat Transfer
In industries such as steel producers, molds vibrate while the shell cools the moving liquid pool. Such a phenomenon is exciting and has to be considered in numerical analysis. There is a wide range of application that combines heat transfer and moving parts. Therefore, this training case demonstrates how to set-up the ACMI boundary condition correctly.
Arbitrary Water Pumpe
Simplifications to the numerical continuum are used in computational fluid dynamics applications almost in every scenario. In most cases, particular regions are not of primary interest. An example is given in the following training case, in which a water pump (which is just generating a pressure drop) is removed and replaced by a 1D cyclic boundary condition. The simplification leads to less numerical cells and, therefore, a reduction of computational costs.
Free Convection in a Solar Chimney
In a wide range of engineering applications, the buoyancy force is the main driving force for the fluid flow. However, in the case of numerical investigations, engineers do have problems in setting up such cases or run into troubles/crashes with OpenFOAM®. This training case shows the set-up and geometry preparation of a more complex application.
Gin Tonic (Conjugated Heat Transfer)
Heat transfer problems, including several different regions, are state of the art simulations for CFD engineers. In each engineering application, heat transfer processes occur. Depending on the investigation, energy transport can be one of the significant quantities for which others are derived, such as thermal-induced stresses or buoyancy effects, which are based on temperature differences. The training case provides the correct set-up for such kind of problems and will guide the trainee through the different steps.
A multiphase simulation using the solver interFoam to investigate into falling droplets. The training case was invented 2017 with a former colleague Christian Gomez Rodrigues to proof an interesting statement. Based on Holzmann CFD's lack of knowledge in the field of droplets, Weber number and so on, the case is more related to be a fun investigation rather than a scientific investigation. An outcome of the fast set-up is the beautiful fluid dynamics and the corresponding velocity field.
Everybody is aware of a windscreen washer build in a car. However, most of the people think that there is a nozzle which is distributing the water onto the windscreen. This training case demonstrates the proper work of such a device. It is not a nozzle nor a mechanically driven spray generation. By using deliberate geometric designs, a fluid induced instability is generated which distributes the outcoming water stream periodically onto the object it is aimed.
Vertical Axial Wind Turbine (VAWT)
Flow-induced rotations are state of the art problematics in computational fluid dynamics analysis such as wind turbines or Kaplan turbines. OpenFOAM® offers the possibility to use an existing library, namely the Six Degree of Freedom (6DoF) library, to model such a phenomenon. This training case will guide you through the necessary steps to simulate flow-induced rotations. The well known and structured Holzmann CFD's run script is generating the whole case automatically, and therefore, you can understand and follow each step.