NX Space Systems Thermal™
NX Space Thermal for NX Advanced Simulation environment is an industry-specific vertical application for thermal analysis of space systems.
Specific capabilities for the Space industry
- Orbital models for all planets of our solar system at any specific point in time and attitude
- Powerful and fast view factor calculations (including parallel computing for large space thermal models)
- Powerful and smart view factor transient re-calculations for the case of articulation simulations, such as for solar panel joints rotation allowing constant pointing at the sun or antenna pointing to specific location
- Efficient transient solution for thermal shock transient analyses during eclipse
- Multi-layer shells specific formulation for MLI and TPS applications
- Interfaces to:
– SINDA
– TSS
– TRASYS
– ESTAN
– ESARAD
– Thermica
NX Space Systems Thermal solver capabilities
- Steady-state (linear and nonlinear)
- Large selection of 1D/2D/3D linear and parabolic finite element types supported
- Material nonlinear thermal properties
- Multi-layer shells for MLI and TPS applications
- Axi-symmetric modeling
- Cyclic thermal problems
- Iterative conjugate gradient solver technology
- Fully coupled conduction, radiation and convection heat transfer simulation
- 1D duct and hydraulic network elements
- Motion and articulation modeling (translational motion and rotational joints)
Thermal Coupling technology for modeling thermal contacts within NX assembly
- Thermally connect disjoint and dissimilar mesh faces and edges
- Surface-to-surface, edge-to-edge or edge-to-surface contact modeling between parts: constant, time or temperature-dependent coefficient of heat transfer, resistance or conductance
- Radiative exchange between disjoint part faces, and faces within a single part
- Interface modeling between connected parts: constant, time or temperature-dependent coefficient of heat transfer, resistance or conductance
- Convective exchange correlations between faces: parallel plates, concentric spheres or cylinders
- Join
- One Way heat transfer
- User defined
- Connection break, Series or T-junction
Applied heat loads
- Constant and time-dependent:
– Heat loads
– Heat flux
– Heat generation - All applied loads can be controlled with temperature-controlled thermostat conditions or PID controllers
- Radiative heating
- Peltier coolers modeling
- Electrical joule heating
Optical, material and surface properties
- Electrical resistivity
- Phase change and ablation properties
- Extinction coefficient
- Refraction
- Bi-variate tables
- Transmissivity/specularity
- Angle-dependent optical properties
Conduction heat transfer
- Handles large conduction models (memory efficient data scheme)
- Temperature-dependent conductivity, specific heat
- Orthotropic conductivity
- Heat of formation at phase change temperature
Temperature boundary conditions
- Constant temperature for steady-state or transient
- Time varying for transient and for nonlinear steady-state
- Thermostat temperature controls or PID controllers
Convection heat transfer
- Constant, time and temperature-dependent heat transfer coefficients
- Parameter and nonlinear temperature gradient functions
Free convection
- Correlation-based free convection to ambient for inclined plates, cylinders and spheres
Forced convection
- Correlation-based convection for plates, spheres and cylinders in forced fluid flow
Radiation heat transfer
- Constant and temperature-dependent emissivity
- Multiple radiation enclosures
- Diffuse view (form) factor calculations with shadowing
- Net view (form) factor calculations
- Adaptive scheme for view (form) factor sum optimization
- Hemicube-based view (form) factors calculation using graphics card hardware
- Radiation patch generation to condense large element-based radiation models
- Radiation matrix controls and parameters
- Additional radiation request types:
– Among group
– Group-to-group
– Monte Carlo calculation method
– Enhanced radiation with Ray Tracing
Initial conditions
- Starting temperatures for both steady-state and transient
- Starting temperatures from previous solution results, from file
Solver solution attributes
- Restart conditions
- Cyclic convergence criteria
- Direct access to solver parameters
- Solver convergence criteria and relaxation factors
- Solver monitor with solution convergence and attributes
- Intermediate results display and recovery directly from solver progress monitor
- Open Architecture (user subroutines)
- Support to include external files
Other features
- Results Reporter
- Summary of results to MS® Excel worksheets
- Heat flow calculation between groups
- Heat maps
- Complete or partial deactivation of selected elements (for radiation form factors calculations)
- Temperature mapping for Nastran FE models
Results post-processing
- Temperatures
- Temperature gradient
- Total load and flux
- Conductive flux
- Convective flux
- Convection coefficients
- Residual
- Heat map
- View factor sum
