Space industry imposes very high reliability and performance requirements. Low weight in combination with very harsh operating conditions require to perform many analyzes to verify functionality of components and integrated devices.
Simulation Of Particulate Contamination
Particulate contamination may affect equipment reliability and performance. In the space industry particulate contamination is under very precise control.
Maintaining certain levels of cleanliness is associated with certain costs. Devices in orbit can no longer be cleaned - particles that settle on them and are not removed before launch will remain there and may reduce the performance of optical elements, cooling surfaces, and solar panels. Predicting particle contamination is possible by performing simulations that reflect the conditions during the payload production process, after placing them in the launcher and during the launch phase.
CIM-mes together with ESA is developed a dedicated software tool to simulate particulate contamination before and during the launch phase.
Structural FEM analysis
FEM analysis gives opportunity to predict loads and structure deformations. Obtained simulation results allow to assess the design and introduce appropriate modifications. Calculations can be performed both in the linear and non-linear range, taking into account contacts and plasticity.
Even the best-balanced rotating elements generate the excitation proportional to the rotational speed, which makes necessary to analyse Campbell charts and verify that natural frequencies are above the excitation frequency.
Fatigue calculations are required when variable cyclic loads occur. To determine the fatigue strength the Wöhler and Goodman charts may be used.
The crack initiation usually occurs at the weld edges of the elements due to stress concentration. We perform crack propagation calculations on the basis of Paris's law and the integral J.
Devices in space operate in very high temperature gradients. These gradients originate from the nature of heat transfer in space (mainly by radiation) or from use of cryogenic fuels and oxidants (e.g. rocket engine turbopumps). Most often it is necessary to perform time-dependent thermal simulations. Resulting temperature maps may be used in structural simulations to account the thermal stresses at specific moments.
Flow Simulations (CFD)
Fluid flow occurs in many launcher and satellite components. Simulations allows to predict the effectiveness of devices and verify their operating parameters. An example of such simulations is a LOx turbopump in which the gaseous methane is used to drive the liquid oxygen pump.
The flow simulation may also include chemical reactions (e.g. combustion) that can affect the fluid density and energy transfer.
Many space devices operate in phase change conditions (e.g. heat pipes). CFD simulations may cover phase change and take into account the latent heat.