Effective algorithms of physical media numerical modeling problems’ solution are discussed. The computation rate of such problems is limited by memory bandwidth if implemented with traditional algorithms. The numerical solution of the wave equation is considered. A finite difference scheme with a cross stencil and a high order of approximation is used. The DiamondTorre algorithm is constructed, with regard to the specifics of the GPGPU’s (general purpose graphical processing unit) memory hierarchy and parallelism. The advantages of these algorithms are a high level of data localization, as well as the property of asynchrony, which allows one to effectively utilize all levels of GPGPU parallelism. The computational intensity of the algorithm is greater than the one for the best traditional algorithms with stepwise synchronization. As a consequence, it becomes possible to overcome the above-mentioned limitation. The algorithm is implemented with CUDA. For the scheme with the second order of approximation, the calculation performance of 50 billion cells per second is achieved. This exceeds the result of the best traditional algorithm by a factor of five.

Low performance is considered one of the main drawbacks of laser powder bed fusion (LPBF) technology. In the present work, the effect of the AlSi10Mg powder layer thickness on the laser melting process was investigated to improve the LPBF building rate. A high-fidelity simulation of the melt pool formation was performed for different thicknesses of the powder bed using the Kintech Simulation Software for Additive Manufacturing (KiSSAM, version cd8e01d) developed by the authors. The powder bed after the recoating operation was obtained by the discrete element method. The laser energy deposition on the powder particles and the substrate was simulated by ray tracing. For the validation of the model, an experimental analysis of single tracks was performed on two types of substrates. The first substrate was manufactured directly with LPBF technology, while the second was cast. The simulation was carried out for various combinations of process parameters, predominantly with a high energy input, which provided a sufficient remelting depth. The calculations revealed the unstable keyhole mode appearance associated with the low absorptivity of the aluminum alloy at a scanning speed of 300 mm/s for all levels of the laser power (325–375 W). The results allowed formulating the criteria for the lack of fusion emerging during LPBF with an increased layer thickness. This work is expected to provide a scientific basis for the analysis of the maximum layer thickness via simulation to increase the performance of the technology.

An implementation of FDTD method for solution of optical and other electrodynamic problems of high computational cost is described. The implementation is based on the LRnLA algorithm DiamondTorre, which is developed specifically for GPGPU hardware. The specifics of the DiamondTorre algorithms for staggered grid (Yee cell) and many-GPU devices are shown. The algorithm is implemented in the software for real physics calculation. The software performance is estimated through algorithms parameters and computer model. The real performance is tested on one GPU device, as well as on the many-GPU cluster. The performance of up to 0.65 • 10¹² cell updates per second for 3D domain with 0.3 • 10¹² Yee cells total is achieved.

We present a simulat ion platform which serves as an integrated fra mework for mu ltiscale and mu ltiphysics modeling of Organic Light Emitting Diodes (OLEDs) and their co mponents. The platform is a imed at the designers of OLEDs with various areas of e xpert ise ranging fro m the fundamental theory to the manufacturing technology. The platform integrates an extendable set of in-house and third-party computational progra ms that are used for predict ive modeling of the OLED parameters important for device performance. These computational tools describe properties of atomistic, mesoscale and macroscopic levels. The plat form automates data exchange between these description levels and allows one to build simu lation workflows and manage re mote task e xecution. The integrated database provides data exchange and storage for the ca lculated and e xperimental results.