We developed a number of versatile computational codes with many features not available in commercial software packages. These codes are briefly reviewed below.

• General-purpose molecular dynamics code.

• Specially designed for simulations of carbon nanotube (CNT) systems (CNT networks and forests, CNT-based nanocomposites) and other nanofibrous materials.

• Implements a complex mesoscopic force field based on the mesoscopic tubular potential [Ref,Ref] describing non-bonded van der Waals interaction between carbon nanotubes.

• Available in both serial and parallel, MPI-based versions.

• Scalability of the parallel version is tested in simulation with 2048 MPI processes for samples containing tens of thousands of CNTs and ~50 millions of particles of a molecular target.

• Includes many additional utilities for generation of CNT networks, forests, and nanocomposite samples, analysis of structural parameters of CNT networks, calculations of effective thermal conductivity and gas permeability of CNT networks, granulometric, cluster, and percolation analysis of CNT systems, etc.

• Results of simulations performed with this code are used in a number of publications on structural [Ref, Ref, Ref, Ref] and thermal [Ref,Ref,Ref, Ref ] properties of CNT networks, laser ablation of CNT systems dissolved in a molecular matrix [Ref], gas permeability of CNT films [Ref], and modelling of energy dissipation in CNT networks in high-velocity impact and ballistic protection applications [Ref].

• Current developments focus on the implementation of a new version of the tubular potential greatly enhancing computational efficiency for large CNT systems.

• General-purpose direct simulation Monte-Carlo (DSMC) code for simulations of the rarefied gas and particulate flows.

• For gas flows: Hard Sphere (HS), Variable Hard Spheres (VHS), VHS-Larsen-Borgnakke models for simulation of collisions between gas molecules; Chemical reactions; Maxwell models of scattering of gas molecules at interfaces, Hertz-Knudsen model of evaporation.

• For particulate flows: Arbitrary particle size distribution; Model of inelastic collisions between rotating rough spherical particles; Model of inelastic particle-surface collisions based on the empirical restitution coefficients of particle velocity; Force, torque, and heat flux exerted on a solid particle from the prescribed gas flow field.

• Multi-block Cartesian meshes build in Cartesian, cylindrical, and spherical coordinates with cut cells at the complex boundaries and local adaptation based on the hierarchical cell subdivision.

• Different meshes for collision and macroscopic parameters sampling.

• Arbitrary grouping of species in gas mixtures for calculation of macroscopic parameters.

• Special algorithms for data sampling in unsteady processes.

• Available in both serial and parallel, MPI-based versions.

• Scalability of the parallel version is tested in multi-billion simulations with up to 4096 MPI processes.

• Spatial weights for simulations of axisymmetric flows.

• Bird's "No Time Counter" (NTC) scheme for the collision sampling.

• Runge-Kutta solvers for particle trajectories in external force fields.

• Tracking of massless and inertial particles and droplets in steady-state/non-stationary gas fields.

• Moving interfaces/boundaries.

• Inertial/non-inertial frames of reference.

• Object-oriented code easily adopted for new geometries and models.

• On-demand preprocessor optimization for one-, two-, or three-dimensional flow problems.

• The code was applied to a series of problems, including aerodynamics of a spinning sphere [ Ref, Ref, Ref, Ref], laser plume expansion in a background gas [Ref, Ref, Ref], continuous wave laser evaporation of an aluminum target, vapor expansion and burning in an external shear flow [Ref], and three-dimensional flow over a rotating comet nuclei [Ref].

• Current developments focus on the implementation of the chemical reaction models and the load balancing algorithm for parallel simulations.

• Direct simulation Monte Carlo (DSMC) code specially designed for kinetic simulations of thermally escaping gas flows in upper planetary atmospheres in the presence of an external gravitational field.

• Hard Sphere (HS)/Variable Hard Sphere (VHS)/VHS-Larsen-Borgnakke models of collisions between gas molecules.

• Gas mixture flows with arbitrary number of species.

• Computational meshes are designed to account for the strong dependence of the number density on the radial distance. Computational meshes, statistical weights, and other numerical parameters can be changed during a simulation in order to achieve best computational performance.

• 3D/2D/1D versions of the code are available. 1D version of the code is optimized for simulations in domains with 1-million-km length scale and includes algorithms for the extended flow analysis.

• Available in both serial and parallel, MPI-based versions. Parallel version includes the load balancing algorithm.

• Scalability of the parallel version is tested in simulation with up to 512 MPI processes.

• A special version of the code is developed for sublimation-driven atmospheric flows that couples the DSMC simulations of the atmosphere with the 3D thermal state of the planetary body surface based on full 3D [Ref] and asymptotic [Ref] thermal models of a rotating and sublimating body illuminated by a light source. Sublimation/condensation processes at the surface provides two-way coupling between the flow and surface thermal state. This version of the code is intended for simulations of rarefied comet and KBO atmospheres.

• Results of simulations performed with this code were used in a number of our publications on thermal escape from planetary atmospheres [Ref, Ref, Ref, Ref, Ref,Ref, Ref, Ref].

• Current developments focus on the implementation of realistic 2D/3D models of the star radiation absorption in the upper atmosphere and coupling thermal/non-thermal escape processes.

• General-purpose 2D multiphase hydrodynamics code for simulations of planar and axisymmetrical incompressible fluid flow.

• The code has special features for simulations of laser melting of various targets with changing the free surface driven by the evaporation, recoil effect of vapor pressure, and Marangoni effect.

• Based on the numerical solution of the incompressible Navier-Stokes equations with the artificial compressibility approach and high-order upwind differences on moving structured meshes.

• Enthalpy formulation for melting/solidification.

• Front tracking for free surfaces.

• Geometric conservation law for simulations on moving meshes can be optionally used.

• Only serial version is currently available.

• Current developments focus on the modelling of coupled gas and liquid flows separated by a free surface.

• General-purpose serial 1D code of compressible hydrodynamics developed for the research and teaching purposes.

• Numerically solves the compressible Navier-Stokes equations with the Lax-Wendroff, MacCormick, and a number of shock-capturing, TVD schemes.

• Solves flows with Cartesian, cylindrical, or spherical symmetry.

• Can be used with an arbitrary multiphase equation of state (EOS) .

• Multiphase EOSs for metals and water (IAPWS) are implemented.

• Diffuse interfaces between phases.

• Optionally includes models for non-equilibrium phase transitions.

• Simulations of flows in an external force field and/or absorption of radiation from an external light source.

• This code was used for modelling thermal and mechanical processes induced by laser heating of a nanoparticle surrounded by a fluid [Ref,Ref], non-equilibrium laser melting of metal targets [Ref], and hydrodynamically escaping flows in planetary atmospheres [Ref].

• The code combines a continuum/CFD model for a carrier gas flow with a kinetic/DSMC model for solid particles.

• The CFD part of the code solves 2D planar/axisymmetrical compressible Navier-Stokes equations with MacCormick and/or Harten's TVD scheme on multi-block overlapping computational meshes.

• The DSMC part of the code solves 3D/2D planar/axisymmetrical particulate flows with the DSMC method. This part of the code is identical to the DSMC/GP3 code described above.

• Both parts of the code, CFD part of the carrier gas flow and DSMC part for solid particles, are fully coupled with each other through terms describing gas-particle interaction.

• A special module allows for the simulation of 2D steady-state particle phase flow fields based on the Lagrange approach [Ref].

• The code was used in a number of publications on dusty gas flows over blunt bodies [Ref,Ref, Ref,Ref,Ref, Ref,Ref,Ref, Ref], two-phase wakes [Ref, Ref], and supersonic two-phase jets [Ref] (The results reported in this work were actually obtained with another stand-alone code specially designed by Vladimir V. Semionov for the jet flow problems).

• Generates 3D, 2D, and 1D ("bundle") random systems of soft-core/hard-core spherocylinders.

• Performs cluster analysis and calculates multiple structural properties of stick systems.

• Solves thermal transport problems in systems of soft-core spherocylinders with arbitrary intrinsic conductivity and contact conductance.

• Serial code with implicit iterative solvers.

• Results obtained with this code were used for comparison with theoretical calculations of thermal conductivity of entangled CNT networks [Ref], CNT bundles [Ref], and will be used in a number of our forthcoming publications.

• Solves the unsteady 3D heat conduction equation for a rotating and sublimating body illuminated by a light source.

• Arbitrary bodies with the surfaces described in terms of the Legendre polynomials.

• Arbitrary body rotation.

• Direct numerical solution of the heat conduction equation is performed with the Crank-Nicholson scheme and iterative solvers.

• Includes an original asymptotic model [Ref] for fast and accurate solutions of the heat transfer problems in the case of periodic body rotation at high Fourier number.

• The code was applied for simulations of the thermal state of rotating comet nuclei [Ref,Ref], laser evaporation of an aerosol particle [Ref], and for parametric study of the gas production by a rotating sphere illuminated by a light source [Ref].

• Currently, the code is coupled with the DSMC/E3 code for simulations of sublimation-driven rarefied atmospheric flows.