validation.md (6516B)
1 # Validation 2 3 This webpage provides the references to validations of the Stardis code 4 and the theoretical framework it is based on. 5 6 1. We first present [validations against analytical model](#analytical), 7 which are directly provided in Stardis as non-regression tests. 8 9 2. We then [refer to scientific papers](#papers) in which Monte Carlo 10 algorithms are compared to deterministic solvers on non trivial 11 configurations. 12 13 3. Finally, we present [a validation test case of SYRTHES](#SYRTHES), 14 the thermal code developed by *Électricité de France*, which 15 provides both a finite element solver and a Monte Carlo solver 16 powered by Stardis. 17 18 <span id="analytical"/> 19 20 ## Comparison against analytical results 21 22 Stardis provides comparisons against analytical solutions. 23 These non-regression tests are available in the `src/` directory of 24 [Stardis Solver](https://gitlab.com/meso-star/stardis-solver/-/tree/master/src) 25 (denoted by `test_*`). 26 Note that the tests are performed on the direct Monte Carlo simulation 27 and the propagator (path-replay with different conditions) when 28 possible. 29 For each test, the scene geometry and 30 physical parameters are described in the header. 31 Among these, we note the following tests: 32 33 - [test\_sdis\_conducto\_radiative.c](https://gitlab.com/meso-star/stardis-solver/-/blob/master/src/test_sdis_conducto_radiative.c) 34 validates the steady resolution of the coupled conduction and 35 radiative transfer in a solid surrounded by two different fluids 36 (left/right faces). 37 38 - [test\_sdis\_convection\_non\_uniform.c](https://gitlab.com/meso-star/stardis-solver/-/blob/master/src/test_sdis_convection_non_uniform.c) 39 validates the transient resolution of the convection for a fluid 40 inside a cube with faces of different known temperatures. 41 42 - [test\_sdis\_transient.c](https://gitlab.com/meso-star/stardis-solver/-/blob/master/src/test_sdis_transcient.c) 43 validates the transient resolution of conduction in nested cubes. 44 45 - [test\_sdis\_solve\_boundary.c](https://gitlab.com/meso-star/stardis-solver/-/blob/master/src/test_sdis_solve_boundary.c) 46 validates the steady computation of the boundary temperature on a 47 solid cube interfaced with a fluid with known temperature. 48 49 - [test\_random\_walk\_robustness.c](https://gitlab.com/meso-star/stardis-solver/-/blob/master/src/test_sdis_solid_random_walk_robustness.c) 50 validates the random walk in a solid with / without a source term in 51 complex geometry. 52 53 <span id="papers"/> 54 55 ## Cross-comparison against deterministic solvers 56 57 Stardis is also validated against usual deterministic codes, on more 58 complex geometries where no analytical solution exists. 59 We list here the academic papers which include such validations and 60 provide a description of the configuration and mention the code used for 61 comparison. 62 63 1. [Penazzi et al.](https://doi.org/10.1016/j.cpc.2023.108911), 64 "Path integral formulations leading to propagator evaluation for 65 coupled linear physics in large geometric models", Computer Physics 66 Communications 2024, appendix C. 67 - Validation against [COMSOL](https://www.comsol.fr/) 68 - Solid with fluid cavities 69 - Coupled conduction, convection (perfectly mixed cavity) and 70 radiation; homogeneous coefficients 71 - Stationary state 72 - Validation of the propagator 73 74 2. [Ibarrart et al.](https://hal.science/hal-03818899v2), 75 "Advection, diffusion and linear transport in a single path-sampling 76 Monte-Carlo algorithm: getting insensitive to geometrical 77 refinement", Preprint 2022, figures F.9 and F.10. 78 - Validation against [COMSOL](https://www.comsol.fr/) or 79 [ANSYS Fluent](https://www.ansys.com/products/fluids/ansys-fluent) 80 - Poiseille duct or Kelvin cells 81 - Coupled conduction, convection (with advection) and radiative 82 transfer; homogeneous coefficients 83 - Stationary state 84 85 3. [Caliot et al.](https://hal.science/hal-02096305v1), 86 "Combined conductive-radiative heat transfer analysis in complex geometry 87 using the Monte Carlo method", Eurotherm 2018, figures 6 to 9. 88 - Validation againsta 89 [ANSYS Fluent](https://www.ansys.com/products/fluids/ansys-fluent) 90 - Kelvin cells 91 - Coupled conduction and radiative transfer 92 - Stationary state 93 94 4. [Retailleau et al](https://hal.science/hal-04059892), 95 "Résolution d’un problème de transferts thermiques couplés en géométrie 96 urbaine par la méthode Monte Carlo", in SFT 2023, figure 4. 97 - Validation against finite differences 98 - Slab with Robin conditions 99 - Coupled conduction, convection (perfectly mixed cell) and 100 radiative transfer 101 - Un-stationary state 102 103 <span id="SYRTHES"/> 104 105 ## Stardis in SYRTHES 106 107 Stardis is used in the 108 [SYRTHES](https://www.edf.fr/en/the-edf-group/inventing-the-future-of-energy/r-d-global-expertise/our-offers/simulation-softwares/syrthes) 109 code of the French electric company *Électricité de France*. 110 Both deterministic and stochastic resolutions can therefore be compared 111 on the exact same CAD input. 112 Here we provide the validation on one stationary test case of 113 conduction inside a [square](#figure1). 114 Both the finite elements and the Monte Carlo (using Stardis) resolutions 115 are [compared](#figure2). 116 117 <span id="figure1"/> 118 119 <figure style="text-align: center"> 120 <img src="images/geometry.svg" alt="geometry" 121 style="width: 50%; display: inline;"> 122 <a href="images/temperature.png"> 123 <img src="images/temperature.png" alt="temperature" 124 style="width: 45%; display: inline;"> 125 </a> 126 </figure> 127 128 > The left figure describes the configuration of the test case. 129 > The system to be simulated is a solid square with one edge having a 130 > known temperature. 131 > Another edge has a convective exchange with a fluid whose temperature 132 > is also known. 133 > The two other edges are adiabatic. 134 > The right image illustrates the temperature field corresponding to 135 > this configuration at steady state. 136 137 <span id="figure2"/> 138 139 [](images/TprofY.png) 140 [](images/TprofX.png) 141 142 > Validation of the Finite element solver and the Monte Carlo solver 143 > (i.e. Stardis) of SYRTHES against the analytical solution of the test 144 > case [presented above](#figure1). 145 > Both curves are computed at steady state at probe positions varying 146 > along the X axis (Top) or the Y axis (Bottom). 147 148 The version of SYRTHES used for this validation is still on development 149 and available on-demand. 150 Please [contact us](mailto:contact@meso-star.com) to obtain this 151 version.