Solution

The migration of ions of the active ingredient through the carrier substance and the tissue follows the electric current density vector field.
However, biological tissue is not just an electric ion conductor but shows significant dielectric permittivity, too. Therefore a surface charge builds up at the boundary between tissue and carrier substance. In case of a pulsed driving voltage the electric current density will contain components required for charging and discharging.
Within the ANSYS FEM-model both properties, i.e. conductivity and dielectric permittivity, are defined for each material in one and the same simulation. The transient simulation returns the time-dependent current density vector field including the components required for boundary (dis-)charging.
The effective ion flow impacting the 3D skin surface is finally obtained by time-averaging the current density at each point of the boundary.

Customer Benefit

The simulation results reveal optimum operating parameters for moving the active ingredient to the desired location in the tissue:

• Evaluating the migration rate especially into pores of different size
• Understanding the effect of various dynamic signal parameters like signal shape and frequency on the migration rate;
  optimization of the driving signal
• Optimizing the shape and size of the active electrode

CADFEM_Anwendungsfall_Braun_Iontophoresis-englisch_2014-05-14_01.pdf

Furthermore, the influence of antenna geometrical dimensions on equivalent circuit parameters like resistance, inductance matrix and parasitic capacitances of each coil had to be precisely determined in order to guarantee appropriate tuning of the resonant system in the MHz range.

Solution

Running parametric studies in ANSYS Maxwell using 3D eddy current harmonic analyses, and current conduction analyses including surrounding insulator electrical field allowed to calculate all required RLC and coupling parameters as a function of input parameters like eye position and antenna dimensions.
A comparison between calculated and measured inductance values showed an agreement within 0.8%.

Customer Benefit

Following this study Sensimed has gained:

• A useful design to start experimental validation and production without extensive iterative prototyping.
• Increased knowledge about the influence of geometrical dimensions on the resonant circuit tuning.

Consulting_Flyer_Sensimed_Wireless_Telemetry_System_RF- Maxwell_.pdf "

Solution

An electrostatic simulation was used with adapted maximum voltages. The computation of the voltages (fig. 2) and electric field (fig. 3) in the miscellaneous components of the circuit breaker allowed to gain an accurate knowledge about the field distribution. Since even tiny geometric details are potential threats, the exact consideration of the detailed geometry allowed to pinpoint the most critical locations of the design. Since miscellaneous structural components and gases have different electrical breakdown limits, several electric field limits have been considered to qualify the design. The numerical simulation was done to compare the field distribution and compliance of critical limits for the standard and new operating voltages.

Customer Benefit

 Following this study Richard AG has gained:

• A validation of the new operating conditions.
• Increased knowledge of the circuit breaker design including an identification of the most critical locations.
• Local information not accessible with experimental measurements.

CADFEM_Anwendungsfall_Richard_Circuit_Breaker-2014-05-14_01.pdf

Finite Element Analyses determine reliable thermo-mechanical stresses due to the compression process of the airfuel mixture, combustion, exhaust outlet and the air fuel mixture inlet. Here the analysis considers the engine's cooling process in combination with the combustion cycle as well as the thermal interaction between fluid and structure within the cylinder head.

Solution

A CFD analysis by ANSYS CFX covering the cooling and combustion process determines the thermal behavior within the engine and provides the basis used for a subsequent stress analysis. This mechanical analysis implies several load cases describing the combustion cycle as well as temperature dependent material properties and nonlinear contacts in a comprehensive finite element model (3,200,000 nodes and 60 nonlinear contact regions). Thermo-mechanical stresses within critical regions of the engine are determined for a subsequent durability analysis in a non-linear ANSYS FE simulation. Further results focus on the contact behavior and the deformation of specific parts and the entire model. The complex analysis of the engine behavior provides information about the contact pressure and possible gaps occurring within the combustion cycle. This information is used to rule out undesired effects on the thermo-mechanical behavior of the engine and its several parts already in the design phase.

CADFEM_Anwendungsfall_MAN_Thermalspannung_englisch-2014-05-14.pdf

fileadmin/PDFs/Service/Simulation_im_Auftrag/Anwendungsfall_SBN_Schweissen_2014.pdf

The goal for the new generation of Luwa's Axial Flow Fan was a lower power consumption, higher fan capacity and lower noise level.
CADFEM was appointed to examine the structural integrity of the fan blades. In operation the blades shall not get into resonance while being subjected to centrifugal and aerodynamic loads.

Solution

To avoid resonance the rotordynamical behavior was studied by modal analysis including gyroscopic effects. The calculated eigenmodes were then judged by Campell- and SAFE-diagram to rule out interactions of rotation speed, disc nodal diameter and blade eigen- frequencies. Several geometry evolutions of the blade were evaluated to reach this target. When the dynamic behavior was sufficient, the strength proof could be carried out. In the first load step bolt pretension was applied to simulate the assembly of the fan runner. In the second load step the rotational velocity and the aerodynamic pressures calculated with ANSYS CFX were applied. The stresses calculated were evaluated using WB/FKM from the CADFEM ihf Toolbox. WB/FKM is an implementation of the FKM guideline “Analytical Strength Assessment” inside ANSYS Mechanical (Workbench) and offers an automated assessment of the static and fatigue utilization over the whole surface.

Customer Benefit

Luwa Air Engineering AG was able to improve the design by approx. 4% resulting in 1.2 MW less power consumption on all fans installed per year. The rotordynamic stability and structural integrity was reached without lengthy physical prototyping and testing cycles. In addition, Luwa was able to save the prototype and personnel cost for the five design iterations needed, amounting to more than 80’000 € saved. Through simulation resonance problems could be ruled out from the start and a deeper insight into the behavior could be gained as would have been possible by tests.

Anwendungsfall_LUWA_Rotordynamik_2014.pdf

fileadmin/PDFs/Service/Simulation_im_Auftrag/Anwendungsfall_Siemens_Rotordynamik_2014.pdf

Solution

An electrostatic assumption was used with adapted maximum voltages. Since Electrostatic analyses are not included in the Mechanical module of Workbench, a 3D thermal static analysis was used with adapted units and material properties in order to calculate the electric field in the air and in the structure. The geometrical dimensions of the corona rings were parameterized and an iterative optimization procedure allowed a decrease of the maximum electric field value to a satisfying level.

Customer Benefit

Following this study Pfisterer Sefag has gained;

• A useful design to start experimental validation and production without extensive iterative prototyping.

• Increased knowledge about the influence of geometrical parameters on the electric field

• A private training based on this consulting work with a knowledge transfer that will allow engineers at Pfisterer Sefag to perform similar analyses themselves on future new designs using the intuitive Workbench Mechanical interface.

Consulting_Flyer_Pfisterer_Silicon_Insulators.pdf