Relation between flame chemiionization and variable-volume combustion chamber temperature and pressure

The article presents the results of investigating the relation between flame chemiionization and the flame temperature and pressure in a variable- volume combustion chamber. Functional dependences of flame temperature and maximum pressure on the electron current caused by flame chemiionization, fundamental characteristics of flame propagation and combustion efficiency are presented. Comparison of the temperature calculated by the proposed method with experimental data shows that with the excess air factor of 0.8 to 1.15, the precision is more than 85%. Comparison of the maximum pressure obtained experimentally and calculated by the refined Vibe model, using the proposed formulas, showed good agreement. The results of the work can be used to predict and monitor maximum flame temperature and pressure in the combustion chamber of an internal combustion engine and other power plants using an ionization probe

Agrocluster management model as the innovative-investment development mechanism of rural territories

The article considers the problems of socio-economic development of rural territories and an effective mechanism of solution, the theme of the research, in the conditions of globalization of the economy and Russia's accession to the WTO, is caused by necessity of improvement of management of socio-economic development of rural municipalities in certain regions of Russia

Numerical investigation of spallation neutrons generated from petawatt-scale laserdriven proton beams

International audienceLaser-driven neutron sources could offer a promising alternative to those based on conventional accelerator technologies in delivering compact beams of high brightness and short duration. We examine this through particle-in-cell and Monte Carlo simulations, that model, respectively, the laser acceleration of protons from thin-foil targets and their subsequent conversion into neutrons in secondary lead targets. Laser parameters relevant to the 0.5 petawatt (PW) LMJ-PETAL and 0.6-6 PW Apollon systems are considered. Due to its high intensity, the 20-fs-duration 0.6 PW Apollon laser is expected to accelerate protons up to above 100 MeV, thereby unlocking efficient neutron generation via spallation reactions. As a result, despite a 30-fold lower pulse energy than the LMJ-PETAL laser, the 0.6 PW Apollon laser should perform comparably well both in terms of neutron yield and flux. Notably, we predict that very compact neutron sources, of ~ 10 ps duration and ~ 100 µm spot size, can be released provided the lead convertor target is thin enough (~ 100 µm). These sources are characterized by extreme fluxes, of the order of 10 23 n cm-2 s-1 , and even ten times higher when using the 6 PW Apollon laser. Such values surpass those currently achievable at large-scale accelerator-based neutron sources (~ 10 16 n cm-2 s-1), or reported from previous laser experiments using low-Z converters (~ 10 18 n cm-2 s-1). By showing that such laser systems can produce neutron pulses significantly brighter than existing sources, our findings open a path towards attractive novel applications, such as flash neutron radiography or laboratory studies of heavy-ion nucleosynthesis