Central Ignition Research Articles

Експериментальні дослідження теплофізичних властивостей гірських порід

Purpose. Obtaining data on the thermophysical properties of rock samples of PJSC “CG Pokrovske” under normal conditions in order to increase the versatility of methods for determining the location of the fire source, the location of the fire in the produced space, obtaining an assessment of its condition and monitoring control at various stages of combustion. Research methodology. The article is aimed at studying the characteristics of heat transfer in rocks, in particular at determining the thermophysical properties of rocks, for which experimental studies of thermal conductivity, thermal conductivity and specific heat capacity of rock samples of the Pokrovska mine were carried out with the help of a thermal conductivity analyser TНВ-100 and the influence of humidity on their thermal conductivity was determined properties using the MIT-1 thermal conductivity meter. Results. The obtained data on thermal conductivity, thermal diffusivity and specific heat capacity of siltstone, sandstone and coal samples taken from the “CG Pokrovske” can be used to improve the existing methods of finding the source of the fire and its location in the mined space, as well as to assess and control the state of the fire. The result of such an improvement can be any work in which it is possible to obtain a more universal way of assessing the state of the fire – the fact of an extinguished or burning fire, the temperature in the fire zone, determining the location of the coal ignition centre and, in fact, the fire itself in the mined space. Scientific novelty. It has been established that with an increase in the weight humidity of rock samples, there is a proportional increase in their thermal conductivity, which is explained by the fact that with an increase in humidity, the latter improves thermal contact in places where particles collide, where, first of all, moisture gets into the smallest pores of the material and displaces air from them. Practical significance. In mines, great importance is given to the forecast of temperature indicators when measuring the temperature of the fire rock in the excavation to assess the process of fire development in order to extinguish them as quickly as possible. These indicators are important for the actual assessment of the state of the environment in the centre of its extinguishing, as they are control for determining the cooling of the rocks of the massif and, ultimately, indirectly indicate the fact of a burning or extinguished fire. The thermophysical properties of rock samples obtained as a result of experimental studies make it possible to increase the versatility of fire assessment methods at various stages of its combustion and, in general, to increase the level of endogenous fire safety of coal mines.

Preliminary Cryogenic Layering by the Infrared Heating Method Modified with Cone Temperature Control for the Polystyrene Shell FIREX Target

The infrared (IR) heating method for a central ignition target with spherical symmetry is modified for the axisymmetric Fast Ignition Realization EXperiment (FIREX) target. The challenge is that the FIREX target pretends to be a thermally spherical shell. Our previous simulation studies (A. Iwamoto et al., Fusion Sci. Technol. 56, 427 (2009), A. Iwamoto et al., J. Phys.: Conf. Ser. 244, 032039 (2010)) have shown that the combination of volumetric heating in a fuel and cone temperature control has the potential to finish a uniform fuel layer. We have developed the IR heating system, dedicated to the FIREX target, with exclusive cone temperature control. The ability of solid fuel layering was examined by using an 826 µm polystyrene (PS) shell with a gold cone of 1.2 mm in length instead of the 500 µm FIREX target for easy observation. The system could control the profile of a solid fuel layer in the PS shell target. Eventually, the solid layer with the best sphericity of 92% was formed, and the RMS roughness of the inner surface was 44 - 49 µm in modes 1 to 100 and 14 - 26 µm in modes 5 to 100.

Laminar Burning Velocities of Hydrogen-Blended Methane–Air and Natural Gas–Air Mixtures, Calculated from the Early Stage of p(t) Records in a Spherical Vessel

The flammable hydrogen-blended methane–air and natural gas–air mixtures raise specific safety and environmental issues in the industry and transportation; therefore, their explosion characteristics such as the explosion limits, explosion pressures, and rates of pressure rise have significant importance from a safety point of view. At the same time, the laminar burning velocities are the most useful parameters for practical applications and in basic studies for the validation of reaction mechanisms and modeling turbulent combustion. In the present study, an experimental and numerical study of the effect of hydrogen addition on the laminar burning velocity (LBV) of methane–air and natural gas–air mixtures was conducted, using mixtures with equivalence ratios within 0.90 and 1.30 and various hydrogen fractions rH within 0.0 and 0.5. The experiments were performed in a 14 L spherical vessel with central ignition at ambient initial conditions. The LBVs were calculated from p(t) data, determined in accordance with EN 15967, by using only the early stage of flame propagation. The results show that hydrogen addition determines an increase in LBV for all examined binary flammable mixtures. The LBV variation versus the fraction of added hydrogen, rH, follows a linear trend only at moderate hydrogen fractions. The further increase in rH results in a stronger variation in LBV, as shown by both experimental and computed LBVs. Hydrogen addition significantly changes the thermal diffusivity of flammable CH4–air or NG–air mixtures, the rate of heat release, and the concentration of active radical species in the flame front and contribute, thus, to LBV variation.

Numerical simulation of flame acceleration and DDT(deflagration to detonation transition) in hydrogen-air mixtures with concentration gradients

ABSTRACT In this paper, a coupled new solver is used to simulate the acceleration and deflagration to detonation transition (DDT) of inhomogeneous mixtures flame under obstacle conditions. Analyzed the variations of flame front, pressure and density with time. The experimental results show that the vertical concentration gradient affects the chemical reaction rate in the combustion reaction zone, resulting in the flame front stretching along the “front up-back down.” At the same time, the flame propagation velocity is affected by obstacles. After multi-stage “acceleration-deceleration,” it reaches 2700 m/s at 1.23 m from the ignition center, and the pressure jumps to 5.0 MPa. Finally, the transition from detonation to detonation is completed. It is worth noting that the local explosion point is in the corner of the obstacle or pipe wall. This simulation method is compatible with low Mach number laminar flow, turbulent flow, and compressible reaction flow problems under high Mach number. It provides prospective prediction for flame acceleration and detonation formation during hydrogen combustion and detonation engine operation.

Work process control mechanisms of diesel engine

The article discusses the issue of reducing the specific fuel consumption and improving the environmental performance of internal combustion engines by changing the working process to obtain high-quality and timely heat release as a result of fuel combustion. The purpose of workflow control is to create favorable conditions for fuel ignition. The ways of occurrence of ignition centers in the combustion chamber are considered. The main periods of fuel supply, the duration of ignition depending on the lag time, the combustion process, the influence of the fuel supply advance angle on the environmental parameters of the engine are highlighted. The possibility of controlling the working process during the preparation of the beginning of combustion is substantiated and examples of mechanisms of domestic and foreign analogs that provide control of the working process are given. Conclusion - high performance management of the workflow is provided by the electronic control system - common rail, despite the widespread use of mechanical methods.

Experimental research on the law of flame spreading in the charge bed of a central ignition tube

In order to investigate the development of flame spreading in the charge bed of a central ignition tube, a visualized ignition experiment platform was designed, and experiments were carried out with different ignition charge masses and charge structures. A high-speed image acquisition system was used to record the propagation process of ignition flame in the propellant bed at 10000 frames per second, and a transient pressure recorder was used to obtain the variation of pressure with time and position in the chamber. In addition, a synchronous trigger was used to connect the high-speed image acquisition system, the transient pressure recorder and the ignition system of the experimental platform, giving the system a trigger zero point, which is convenient for the statistical analysis of subsequent experimental phenomena. The experimental results show that the time of flame-appearing from the ignition tube into the combustion chamber is 0.6 ms when the mass of the black powder is 20 g. However, the time increases to 1.5 ms when the mass of the black powder is 30 g. The average flame-spreading time of the stick charge structure is 2.2 ms, the average flame-spreading time of the granular charge structure is 3.4 ms, and the average flame-spreading time of the mixed charge structure is 3.1 ms. The results indicate that the mass of the black powder in an ignition tube has a significant effect on the time of flame-appearing from the ignition tube, and the higher black powder mass lead to the longer flame-appearing time. The performances of flame-spreading in different charge bed structures are quite different. The performance of flame-spreading in the stick charge structures is better than that in the granular charge structures and mixed charge structures. In addition, the pressure fluctuations will appear in the chamber due to gas choking in the granular charge structures. A mathematical model of the flame-spreading process was established by fitting the first-order exponential decay function according to the time sequence of the position of flame, and the goodness of fit is greater than 0.98.

On the explosion characteristics for central and end-wall ignition in hydrogen-air mixtures: A comparative study

To demonstrate the influence of different ignition positions on the explosion characteristics of H2-Air mixtures, a series of experiments at central and end-wall ignition under turbulent and quiescent conditions are carried out in a constant volume spherical container. Three explosion characteristics including explosion time τe, maximum explosion pressure rise rate (dp/dt)max, and maximum explosion pressure pmax are measured and derived from the explosion overpressure curve. The experimental results demonstrate that the explosion hazard with the central ignition is generally stronger than that with the end-wall ignition under quiescent conditions. At lower initial pressure, the difference between two ignition cases is greater. The results show that for central ignition, the energy loss is small, and the explosion behavior is similar to the ideal constant volume explosion. While for end-wall ignition, the interaction between supersonic blast wave and cooling rough wall consumes a large amount of explosive energy. Under turbulent conditions, the increase of the jet pressure pjet and the jet time Tjet leads to the increase of turbulence intensity and duration, which enhances the explosion hazard of central ignition, but restrains the explosion process of end-wall ignition. The difference between the two ignition locations increases with the increase of pjet and Tjet.

A light curve model of V2491 Cyg: Classical nova outburst on a cool and massive white dwarf

Abstract The classical nova V2491 Cyg was once suggested to be a recurrent nova. We have broadly reproduced the light curve of V2491 Cyg by a nova outburst model on a cold 1.36 M⊙ white dwarf (WD), which strongly suggests that V2491 Cyg is a classical nova outbursting on a cold very massive WD rather than a recurrent nova outbursting on a warmer WD like the recurrent nova RS Oph. In the long-term evolution of a cataclysmic binary, an accreting WD has settled to a thermal equilibrium state with the balance of gravitational energy release and neutrino loss. The central temperature of the WD is uniquely determined by the energy balance. The WD is hot (cold) for a high (low) mass accretion rate. We present the central temperatures, ignition masses, ignition radii, and recurrence periods for various WD masses and mass accretion rates. In a classical nova, which corresponds to a low mass accretion rate, the WD is cool and strongly degenerated and the ignition mass is large, which result in a strong nova outburst. In a recurrent nova, the WD is relatively warmer because of a high mass accretion rate and the outburst is relatively weaker. The gravitational energy release substantially contributes to the luminosity during the recurrent nova outbursts. We compare physical properties between classical novae and recurrent novae and discuss the essential differences between them.

Two-dimensional numerical simulation on gas-solid two-phase flow induced by combustion gas flow in a chamber based on a fifth-order WENO scheme

In order to explore the flow characteristics and propagation law of combustion gas from the central ignition tube in the initial stage of internal ballistic, a visual experimental platform was designed to carry out ignition experiments with the substituted particle bed in the chamber. A high-speed camera system was used to capture the gas flow and flame propagation in the chamber, and a dynamic data acquisition and analysis system with pressure sensors was applied to record the pressure data at characteristic positions in the chamber. A two-dimensional, axisymmetrical, two-phase flow model of internal ballistics was constructed to simulate the flow process of the gas in the substituted particle bed based on a weighted essentially non-oscillatory (WENO) scheme, and the time term was determined by the third-order TVD Runge-Kuta method. The calculated results are in good agreement with the visual experimental results, and the global pressure average error is 5.35%. It indicates that the numerical simulation can accurately describe the gas flow characteristics and present the development process of the gas from the ignition tube in the substituted particle bed. The radial effect of the chamber pressure is obvious, and the gas moves rapidly along the radial direction, and the substituted particle basically does not move in the initial stage of ignition. Moreover, with the gradual propagation of the gas in the chamber, the chamber pressure is characterized by a radial uniformity and an axial gradient distribution. Under the action of the pressure gradient, the axial velocity of the gas phase begins to dominate, and furthermore, the radial velocity decreases to zero in the bottom and the middle region of the chamber, while the solid phase velocity varies with the gas phase velocity. In addition, before the gas reaches the bottom of the right end, the inverse velocity fluctuation appears in advance due to the solid particle congestion.

External explosions of vented hydrogen-air deflagrations in a cubic vessel

The effects of hydrogen concentration and ignition location on the external explosion were experimentally investigated during vented hydrogen-air deflagrations in a cubic vessel. Hydrogen concentration ranging from 14 vol% to 50 vol% and three ignition locations (front, center, and back ignitions) were focused with the ambient temperature and pressure of 283 K and 100.5 kPa, respectively. The pressure histories and flame behavior inside and outside the vessel were recorded. Experimental results show that Helmholtz oscillation was always found for front ignition. Three overpressure peaks of Popen, Phel and Pvib resulting from the vent rupture, Helmholtz oscillation and flame-acoustic-oscillation were recorded respectively. For center and back ignitions, an additional overpressure peak Pext, generated by the external explosion, was monitored. Popen was the maximum one for front ignition while Pext became the maximum one with increasing hydrogen concentration for center and back ignitions. However, the maximum overpressure for back ignition was significantly larger than those for front and center ignitions. Only one external overpressure peak was recorded for front ignition. However, as hydrogen concentration was larger than 18 vol%, two external overpressure peaks were recorded for center and back ignitions, and the one induced by the external explosion for back ignition was significantly larger than that for center ignition. Moreover, external explosion affected significantly affects the flame evolution outside the vessel.

Propagation of CH4-N2O-N2 Flames in a Closed Spherical Vessel

Flammable fuel-N2O mixtures raise safety and environmental protection issues in areas where these mixtures are used (such as: industry, research, internal combustion engines). Therefore, it is important to know their laminar combustion velocities and propagation speeds—important safety parameters for design of active protection devices against gas explosions and corresponding safety recommendations. In this paper, the laminar combustion velocities of N2-diluted CH4-N2O flames, obtained in experiments on outwardly propagating flames, at various initial pressures (within 0.5–2.0 bar) and room temperature, are reported. The experiments were made in a 0.5 L spherical cell with central ignition. The laminar combustion velocities were calculated from the constants of cubic law of flame propagation during the early stage of closed cell explosions and the expansion coefficients of unburned flammable mixtures, using the adiabatic model of the flame propagation. The expansion coefficients were determined from equilibrium calculations on flames propagating under isobaric conditions. The laminar combustion velocities were compared with data reported in the literature. Using the laminar combustion velocities and the expansion coefficients, the propagation speeds of N2-diluted CH4-N2O flames were calculated. Both laminar combustion velocities and propagation speeds decrease with the initial pressure increase.

Experimental study of the effects of vent area and ignition position on internal and external pressure characteristics of venting explosion

Explosion venting can cause not only internal damage but can cause external damage to buildings. Since little attention is paid to the damage caused by both explosions simultaneously, vented explosion tests were performed in a 4.5 m3 square chamber, to investigate the internal and external pressure characteristics and their correlation. The results show that ignition location has little effect on venting pressure (P1), but significantly affects the Helmholtz oscillations and high-frequency oscillation pressure (P4). Central and front ignitions lead to the maximum P4 and longest Helmholtz oscillation, respectively; during venting, two pressure peaks (defined as Pe1 and Pe2) were recorded due to the shock wave and combustion wave, respectively. Pe1 has an inverse proportional relationship with distance. Pe2 is proportional to P1. When the vent area exceeds 0.16 m2, Pe2 under rear ignition plays a more dominant role than that of other ignition points, however, the vent area is equal to 0.16 m2, Pe2 with central ignition becomes dominant. The external pressure peaks corresponding to the external flame development were captured. The longest length of the jet flame was observed at central ignition and rear ignition forms the largest external combustion area.

Effects of vessel height and ignition position upon explosion dynamics of hydrogen-air mixtures in vessels with low asymmetry ratios

The explosion characteristics of hydrogen-air mixtures in a wide range of equivalence ratios in closed vessels were investigated experimentally. The maximum explosion pressure, maximum pressure rise rate (along with deflagration index), explosion time and heat loss were evaluated. Three vessels with low asymmetry ratios (H/D) of 0.146, 0.244 and 0.341 were used to study the effect of vessel height on explosion parameters, in which H and D are the height and inner diameter of the vessel, respectively. In the H/D = 0.341 vessel, the effect of ignition position on explosion behaviors was also considered. The results show that, with the increase of the vessel height, the maximum explosion pressure increase correspondingly, and the explosion time decreases orderly. In the lowest height vessel (H/D=0.146), the ignitor-regulating column acts as a ‘turbulence-generator’. Thus, the maximum rate of pressure rise could be increased significantly while the heat loss could be decreased. Compared with the central ignition scenario, both the maximum explosion pressure and maximum pressure rise rate are decreased for the asymmetrical ignition; meanwhile, the explosion time and the heat loss during the explosion are increased.

High-volume and -adiabat capsule (“HVAC”) ignition: Lowered fuel compression requirements using advanced Hohlraums

Lower-than-expected deuterium–tritium fuel areal densities have been experimentally inferred across a variety of high-convergence, nominally low-adiabat implosion campaigns at the National Ignition Facility (NIF) using cylinder-shaped Hohlraums [Hurricane et al., Phys. Plasmas 26, 052704 (2019)]. A leading candidate explanation is the presence of atomic mix between the fuel and ablator from hydrodynamic instability growth [Clark et al., Phys. Plasmas 26, 050601 (2019)], leading to reduced fuel compressibility and an effectively higher (in-flight) fuel adiabat α. Tolerating a high-α implosion can be obtained with significantly higher capsule absorbed energy Ecap according to the one-dimensional (1-D) ignition-threshold-factor analytic scaling [S. Atzeni and J. Meyer-ter-Vehn, Nucl. Fusion 41, 465 (2001)], ITF∼Ecap·α−1.8. Recent experiments with large Al shells in rugby-shaped Hohlraums have established high laser-capsule coupling efficiencies of ≽ 30% [Ping et al., Nat. Phys. 15, 138 (2019)], enabling a path to Ecap≽ 0.5 MJ at the NIF and increased performance margin M ≡ ITF − 1. The ability to operate at high adiabat with large capsules using nonstandard Hohlraums leads to the predicted onset of a volume-ignition mode, defined as when both the entire fuel is the “hot spot” and inertial confinement is principally provided by the ablator compared with the compressed fuel. Such an ignition mode, normally reserved for high-Z targets, e.g., double shells [Amendt et al., Phys. Plasmas 14, 056312 (2007)], is predicted to lead to lower fuel convergence and less exposure to mix due to the intended high adiabat—but at the expense of ∼3–4 × reduced (1-D) yield compared with conventional central hot-spot ignition designs.

Review of hydrodynamic instabilities in inertial confinement fusion implosions

Laser fusion, likely the ultimate solution to the crisis of human energy, is highly valued by the international community and has always been the focus of international research. It turns out that the biggest scientific obstacle of laser fusion is the effective control of the high-energy-density nonlinear flows during implosions. The research of high-energy-density nonlinear flows covers many different fields, such as high-energy-density physics, plasma physics, fluid mechanics, computing science, strong impact physics, and high pressure atomic physics. Meanwhile, the capability of multi-material and multi-scale numerical simulations as well as large laser facility with high output power is also needed. As an emerging research field, it is full of all kinds of novel phenomena to be explored. In addition, hydrodynamic instabilities and the subsequent turbulent mixing in high-energy-density flows, are also important processes in astrophysical phenomena (e.g., galaxy collision and merging, stellar evolution, formation of protostars and supernova explosion) and involve with the core content of astrophysics. This paper reviews, firstly the status and progress, as well as the challenges and opportunities of high-energy-density nonlinear flows research. Secondly, it introduces hydrodynamic instabilities during implosions in central ignition laser fusion, among which, key factors related to the bottleneck of implosion performance of the National Ignition Facility (NIF) in the United States are condensed. Next, it summarizes the development of hydrodynamic instability experiments in laser fusion abroad. Finally, it lists some key achievements on the fundamental issues of hydrodynamic instabilities by the laser fusion implosion physics team in China over the last three years. This team has been engaged in the research and control of nonlinear flows in laser fusion implosions, as well as the research and design of target physics. A lot of improvements have been made in recent years on the theoretical analysis and numerical simulation of outstanding issues for hydrodynamic instabilities in laser fusion implosions, and the design and analysis of experiments on large lasers, which greatly promoted the development of this research direction in China.

Evaluation of an improved CFD model against nine vented deflagration experiments

In the present work, a newly developed CFD deflagration model incorporated into the ADREA-HF code is evaluated against hydrogen vented deflagrations experiments carried out by KIT and FM-Global in a medium (1 m3) and a real (63.7 m3) scale enclosure respectively. A square vent of 0.5 m2 and 5.4 m2 respectively is located in the center of one of side walls. In the case of the medium scale enclosure the 18% v/v homogeneous hydrogen-air mixture and back-wall ignition case is examined. In the case of the real scale enclosure the examined cases cover different homogeneous mixture concentrations (15% and 18% v/v), different ignition locations (back-wall and center) and different levels of initial turbulence. The CFD model accounts for flame instabilities that develop as the flame propagates inside the chamber and turbulence that mainly develops outside the vent. Pressure predictions are compared against experimental measurements revealing a very good performance of the CFD model for the back-wall ignition cases. For the center ignition cases, the model overestimates the maximum overpressure. The opening of the vent cover is identified as a possible reason for the overprediction. The analysis indicates that turbulence is the main factor which enhances external explosion strength causing the sudden pressure increase, confirming previous findings.

Experimental study of overpressure and temperature field behaviors of a methane-air mixture with different ignition positions, solid structure obstacles and initial turbulence levels

For gas explosion accidents occurring in buildings, the explosion characteristics may be affected by the presence of the equipment and furniture, and the temperature produced by the vented explosion threatens the safety of surrounding personal and buildings. To investigate the internal overpressure and external temperature behaviors, explosion venting tests of methane-air mixtures were conducted in a self-designed 4.5-m3 square chamber, by changing the solid obstacles, ignition positions, and initial turbulence levels. The results showed that P1 is generated due to the venting rate exceeding the volume growth rate of products after vent opening; with increasing flame propagation, flame front increases and more folds are present on the surface during venting, when the rate of combustion product exceeds the venting rate again, then P2 forms. Ignition position and obstacles have little effect on P1, but affect the Helmholtz oscillation and high-frequency pressure oscillation (P4). Front ignition leads to the longest duration of Helmholtz oscillation and central ignition results in the largest P4. In the presence of obstacles, P4 is eliminated and strengthened in the cases of rear and front ignitions, respectively. P4 decreases and then increases as a function of the number of obstacles. Front ignition leads to the lowest temperature peak, rear and central ignition results in the same temperature peak. The length of the high-temperature field is the shortest under four obstacles and front ignition, respectively. Under strong initial turbulence, the overpressure peak, length and duration of the high-temperature field are the largest.

Effect of concentration and ignition position on vented methane–air explosions

Experiments were conducted in a 1 m3 vessel with a top vent to investigate the effect of methane concentration and ignition position on pressure buildup and flame behavior. Three pressure peaks (p1, p2, and Pext) and two types of pressure oscillations (Helmholtz and acoustic oscillations) were observed. The rupture of vent cover results in p1 that is insensitive to methane concentration and ignition position. Owing to the interaction between acoustic wave and the flame, p2 forms in the central and top ignition explosions when the methane–air mixture is near–stoichiometric. When the methane–air mixture is centrally ignited, p2 first increases and then decreases with an increase in the methane concentration. The external explosion-induced Pext is observed only in the bottom ignition explosions with an amplitude of several kilopascals. Under the current experimental conditions, flame–acoustic interaction leads to the most serious explosions in central ignition tests. Methane concentration and ignition position have little effect on the frequency of Helmholtz and acoustic oscillations; however, the Helmholtz oscillation lasts longer and first decreases and then increases as the methane concentration increases for top ignition cases. The ignition position significantly affects the Taylor instability of the flame front resulting from the Helmholtz oscillation.

Study of Coulomb collisional effects on the propagation of electromagnetic waves in a turbulent plasma

AbstractThe presence of Weibel instability in laser‐irradiated fuel could be detrimental to the process of ablative implosion, which is necessary for achieving thermonuclear fusion reactions. In this paper, the effect of the Coulomb collisional within the turbulent plasma on the Weibel instability growth rate has been investigated for linear and circular polarization. The results indicate that the Weibel instability growth rate at circular polarization near the ignition centre of the fuel fusion (collisional plasma) is about 105 times higher than the collisional Weibel instability growth rate at linear polarization. The Weibel instability growth rate is observed near the critical density of the fuel fusion (collisionless plasma) at linear polarization and enhancement near the foot of the heat in front of the fuel fusion. By increasing the steps of the density gradient plasma in the low‐density corona, electromagnetic instability occurs at a higher stress flow. Therefore, the deposition condition of electron beam energy in circular polarization of turbulent plasma can be shifted to the fuel core for suitable ignition.

Progress and opportunities for inertial fusion energy in Europe.

In this paper, I consider the motivations, recent results and perspectives for the inertial confinement fusion (ICF) studies in Europe. The European approach is based on the direct drive scheme with a preference for the central ignition boosted by a strong shock. Compared to other schemes, shock ignition offers a higher gain needed for the design of a future commercial reactor and relatively simple and technological targets, but implies a more complicated physics of laser–target interaction, energy transport and ignition. European scientists are studying physics issues of shock ignition schemes related to the target design, laser plasma interaction and implosion by the code developments and conducting experiments in collaboration with US and Japanese physicists, providing access to their installations Omega and Gekko XII. The ICF research in Europe can be further developed only if European scientists acquire their own academic laser research facility specifically dedicated to controlled fusion energy and going beyond ignition to the physical, technical, technological and operational problems related to the future fusion power plant. Recent results show significant progress in our understanding and simulation capabilities of the laser plasma interaction and implosion physics and in our understanding of material behaviour under strong mechanical, thermal and radiation loads. In addition, growing awareness of environmental issues has attracted more public attention to this problem and commissioning at ELI Beamlines the first high-energy laser facility with a high repetition rate opens the opportunity for qualitatively innovative experiments. These achievements are building elements for a new international project for inertial fusion energy in Europe.This article is part of a discussion meeting issue ‘Prospects for high gain inertial fusion energy (part 1)’.