CFD calculation on labyrinth seals

For the CFD Calculation on labyrinth gap seals, both 2D and 3D geometries were considered in a CFD parameter study. This type of seal is a non-contact seal. The sealing effect is based on an extension of the flow path through the gap to be sealed. They are usually used in almost all types of turbomachinery and thus separate areas of different pressure from each other. Learn more about them, how to improve the function and quality of your products by means of CFD calculations can.

CFD parameter study of a labyrinth seal

Due to long simulation times, which are to be expected with the turbulent CFD analysis on the 3D model, a CFD parameter study is first carried out on a 2D geometry with one chamber. Then a CFD model of the 3D flow geometry is analysed, which also takes the wall rotation into account.

Using the simple CFD model, pressure losses and flow velocities are calculated assuming a turbulence value of 5 % and an inlet velocity of 5 m/s examined.

By using the appropriate solver, not only a realistic flow behaviour but also a corresponding density change of the entering air can be detected. In the next step of the CFD parameter study, a CFD model of the two-dimensional cross section of a labyrinth seal with 3 chambers is now built and examined.

CFD analysis on the three-dimensional model of a labyrinth gap seal

To observe the flow on the 3D model, the rotation of the shaft and thus the swirl of the flow field must also be taken into account in the CFD calculation. For this purpose, a simplified formulation of the boundary condition as a rotating wall is assumed. The results of the CFD calculation correctly represent both shaft rotation and the corresponding pressures or velocities at the cross-sections of the chambers, as well as the circulation of the positive and negative pressure areas in the three-chamber geometry.

Depending on the number of revolutions and entry speeds of the fluid, enormous computing times are required to achieve the most realistic representation possible. However, as this parameter study shows, important insights into the flow behavior in labyrinth seals can also be gained by means of a simplified CFD simulation.

Further example project for numerical flow simulation:

• FSI simulation of a cylinder head
• CFD simulation for electronic cooling
• Indoor climate assessment using CFD simulation

If it is a matter of mapping flow effects in and around components within the scope of your project, we will be happy to help you. Inform yourself about our range of services and request a free and non-binding offer today !