Paolo Barbante

• Ph.D. in Applied Sciences, ULB, Belgium
• Researcher at Politecnico di Milano

We perform a quantitative assessment of different strategies to compute the contribution due to surface tension in incompressible two-phase flows using a conservative level set (CLS) method. More specifically, we compare classical approaches, such as the direct computation of the curvature from the level set or the Laplace-Beltrami operator, with a...

Many physical situations are characterized by interfaces with a non trivial shape so that relevant geometric features, such as interfacial area, curvature or unit normal vector, can be used as main indicators of the topology of the interface. We analyze the evolution equations for a set of geometrical quantities that characterize the interface in t...

Many physical situations are characterized by interfaces with a non trivial shape so that relevant geometric features, such as interfacial area, curvature or unit normal vector, can be used as main indicators of the topology of the interface. We analyze the evolution equations for a set of geometrical quantities that characterize the interface in t...

We propose an efficient, accurate and robust IMEX solver for the compressible Navier-Stokes equations describing non-ideal gases with general cubic equation of state and Stiffened-Gas EOS. The method is based on an h-adaptive Discontinuous Galerkin spatial discretization and on an Additive Runge Kutta IMEX method for time discretization. It is spec...

We propose an efficient, accurate and robust implicit solver for the incompressible Navier‐Stokes equations, based on a DG spatial discretization and on the TR‐BDF2 method for time discretization. The effectiveness of the method is demonstrated in a number of classical benchmarks, which highlight its superior efficiency with respect to other widely...

Presentation for HYP2022 conference

We propose an efficient, accurate and robust IMEX solver for the compressible Navier-Stokes equation with general equation of state. The method, which is based on an $h-$adaptive Discontinuos Galerkin spatial discretization and on an Additive Runge Kutta IMEX method for time discretization, is tailored for low Mach number applications and allows to...

We propose an efficient, accurate and robust implicit solver for the incompressible Navier-Stokes equations, based on a DG spatial discretization and on the TR-BDF2 method for time discretization. The effectiveness of the method is demonstrated in a number of classical benchmarks, which highlight its superior efficiency with respect to other widely...

The vapor condensation onto a thin liquid film, induced by the reflection of a weak shock wave, is studied by molecular dynamics atomistic simulations of a simple Lennard-Jones fluid. Molecular dynamics results provide reference flowfields for two models. The first one adopts a hybrid continuum-kinetic description in which the liquid phase is descr...

The interplay of a gas–surface interaction and thermal nonequilibrium is still an open problem in aerothermodynamics. In the case of reusable thermal protection systems, it is unclear how much of the recombination energy is stored internally in the molecules produced by surface catalytic reactions, potentially leading to nonequilibrium between thei...

Self-pressurizing tank dynamics is modeled using a Baer-Nunziato type multiphase model, with relaxation source terms that account for the exchange of momentum, energy and matter among the phases. Numerical results for nitrous oxide are compared to experimental results available in literature. Since the source terms have an infinite relaxation speed...

Evaporating/condensating flows involving liquids wetting nanopores are at the basis of both biological and artificial processes. Contrary to the dynamics of a vapor in contact with a free liquid surface, evaporation/condensation from/to surfaces is strongly affected by the interaction of the liquid-vapor system with the walls. The latter shows up b...

The paper aims at presenting Direct Simulation Monte Carlo (DSMC) extensions and applications to dense fluids. A succinct review of past and current research topics is presented, followed by a more detailed description of DSMC simulations for the numerical solution of the Enskog-Vlasov equation, applied to the study of liquid-vapor flows. Results a...

Boundary-layer transition prediction has a dramatic impact on the optimization of hypersonic cruise and entry vehicle design. Linear Stability Theory approaches laminar-to-turbulent transition in a simplified yet physics-based manner. This work investigates the stability of Mach 10 air flow over an adiabatic flat plate in chemical non-equilibrium a...

The evaporation of a thin liquid film is studied by a diffuse interface model whose thermodynamic and transport properties are consistent with those of the Lennard-Jones fluid. Solutions are obtained for various liquid film temperatures and downstream vapor flow velocities. The results are compared with reference molecular dynamics simulations of a...

Kinetic theory of fluids plays an important role in understanding and modeling mass, momentum and energy transfer between the vapor and liquid phase in non-equilibrium two-phase flows, in which evaporation and/or condensation take place. The paper presents a review of the literature which focuses on kinetic modeling of the vapor-liquid interface. S...

The condensation of a vapor onto a planar liquid surface, caused by the reflection of a weak shock wave, is studied by three different simulation method. The first one is based on molecular dynamics (MD) simulations of the Lennard-Jones fluid which are supposed to provide reference solutions. The second method is based on a Diffuse Interface Model...

Nowadays, numerical simulations of combustion processes in hybrid rockets are generally considered as a qualitative tool used mainly to describe the flow field inside the rocket engine. A research effort is of major importance in order to change this trend, by obtaining results which are quantitatively accurate, to be used as a support for experime...

A kinetic model for the study of capillary flows in devices with microscale geometry is presented. The model is based on the Enskog-Vlasov kinetic equation and provides a reasonable description of both fluid-fluid and fluid-wall interactions. Numerical solutions are obtained by an extension of the classical Direct Simulation Monte Carlo (DSMC) to d...

The development of next generation reusable space vehicles requires a precise qualification of their Thermal Protection System materials. The catalytic properties are usually determined in plasma wind tunnels for sets of test conditions relevant to the planned flight mission program. Therefore, for such a situation, it is important to have a method...

During the (re-)entry phase of a space vehicle, the gas flow in the shock layer can be in a state of strong thermal non-equilibrium. Under these circumstances, the population of the internal energy levels of the atoms and molecules of the gas deviates from the Boltzmann distribution. A substantial increase of the heat flux transferred from the gas...

The unsteady evaporation of a thin planar liquid film is studied by molecular dynamics simulations of Lennard-Jones fluid. The obtained results are compared with the predictions of a diffuse interface model in which capillary Korteweg contributions are added to hydrodynamic equations, in order to obtain a unified description of the liquid bulk, liq...

Hybrid rocket engines are nowadays considered the new frontier for space propulsion due to their low cost, operational flexibility and intrinsic safety. Their multiphase and multi-domain characteristics result in major difficulties in the numerical modeling of the phenomena involved. A reliable numerical model capable of predicting performance para...

A kinetic model for the study of capillary flows in micromechanical devices has been presented. The model is based on the Enskog-Vlasov kinetic equation and provides a reasonable description of two-phase flows and of fluid-surface interaction. The structure of liquid menisci between two hydrophilic walls has been studied and our results agree fairl...

The present work is focused on the stability evaluation of a thin liquid film developing on the surface of low melting temperature solid fuels used in hybrid rocket propulsion systems. The liquid film instability is the key condition for the onset of the entrainment effect, which is responsible for very large increases of the fuel regression rate....

The effects of adsorbed gas layers on gas-surface interaction is investigated by a kinetic model based on the Enskog-Vlasov equation. The onset of collisional effects in the gas layer is studied by equilibrium simulations. The effects of adsorption on the gas-wall friction forces is investigated in a simple Couette flow geometry. It is shown that g...

The development of reentry space vehicles requires a precise qualification of their thermal protection system materials. The material catalytic properties should be determined for test conditions relevant to the real flight mission program. However, perfect reproduction of the flight environment in a ground facility is practically impossible for re...

The computation of entry problems into a planetary atmosphere strongly relies on the models used to describe the thermal and chemical nonequilibrium effects in the flow, the radiation phenomenom, and the surface chemistry. Moreover, the solution of the flow field in the continuum approach also requires an accurate description of the transport prope...

It is customary in literature to approximate diffusion fluxes by means of a simple Fick's law approximation, that is correct only for binary mixtures. Such an approximation is computationally cheap, but can grossly violate the mass conservation constraint and leads to wrong estimation of computed wall heat flux. In this contribution we compare Fick...

The development of next generation reusable space vehicles requires a precise qualification of their Thermal Protection System materials. The catalytic properties are usually determined in plasma wind tunnels for sets of test conditions relevant to the planned flight mission program. Therefore, for such a situation, it is important to have a method...

Development of reusable space vehicles requires a precise qualification of their thermal protection system materials The catalytic properties are usually determined in plasma wind tunnels for test conditions relevant to the flight mission program. Therefore, for such a situation, it is important to have a methodology that allows the correct extrapo...

The paper presents an overview of the aerothermal plasma simulation facilities in use at the von Karman Institute for Fluid Dynamics and the main research topics that have been followed during 10 years of work in the field. Both numerical simulation of plasma flows and experimental techniques are addressed, with an emphasis of the methodology which...

This paper presents a detailed review of the numerical modeling of inductively coupled air plasmas under local thermodynamic equilibrium and under chemical non-equilibrium. First, the physico-chemical models are described, i.e. the thermodynamics, transport phenomena and chemical kinetics models. Particular attention is given to the correct modelli...

Efficient and accurate Hermitian-type multipoint finite difference methods are used to develop a general boundary-layer code for analyzing reacting flows around bodies of revolution. The main motivation is to build a reliable code that can be used for the investigation of the influence of different physico-chemical models for transport properties,...

In this paper, efficient and accurate hermitian type multi-point finite difference methods are used to develop a general boundary layer code for analyzing reacting flows around bodies of revolution.The main motivation is the investigation of the influence of different physico-chemical models for transport properties,chemical kinetics and finite rat...

A review is made of the computational models of high temperature flows developed over the past few years at the von Karman Institute, for the modelling of inductively coupled plasma flows and hypersonic (re-)entry flows. Both flows in local thermodynamic equilibrium and flows in chemical non-equilibrium and thermal equilibrium are considered. First...

This contribution presents an elegant and efficient numerical model of a multi-component inductive plasma under chemical non-equilibrium. The plasma is modeled by a finite number of species. Chemical reactions are taken into account by Arrhenius-type source terms. The plasma thermodynamic properties are computed from statistical mechanics. The plas...

We report on the recent activities to improve the understanding and the modeling of catalysis of silica exposed to air plasma. Such a combination presents a model for a ther- mal protection material during an atmospheric entry flight. First, the finite rate catalysis concept is introduced and exemplified using a model available in the literature, t...