Layout analysis of compressed air and hydraulic energy storage systems for vehicles

The compressed air energy storage system has a better energy density, while the widely used hydraulic one is superior in power performance. Therefore, they are suitable for different hybrid vehicles, which require a comparative study on the performances and vehicle applicability of the broad pressure energy storage system layouts. In this paper, an integrated mathematical model of four basic pressure layouts is presented for characteristic analysis and applicability discussion. Results show that the open volume layout achieves the best power performance with the flow specific power of 13.92 MJ/m3, thus it is suitable for heavy hybrid trucks and mobile machinery. The open mass layout achieves the best energy performance with the energy density of 124.35 MJ/m3, which can be used in light new energy passenger vehicles. And the performance of the closed volume layout is close to the open volume layout with the flow specific power of 9.78 MJ/m3, so it could be applied to middle and light hybrid trucks. This research provides a basis for the hybrid method of pressure energy storage system layouts for vehicles, and could be applied in the design and research of non-electric hybrid vehicles in the near future.

Comparison of Absolute Dose Achievable Between Helical Tomotherapy and RapidArc in Total Dura Mater Irradiation for Child Cancer

Background and Purpose: In this study, the absolute dose achievable between helical tomotherapy (HT) plans and RapidArc (RA) plans for total dura mater irradiation (TDMI) was compared. Materials and methods: A planning study was conducted on nine children's case datasets with dura mater metastasis of neuroblastoma. The target included the entire calvarium and skull base and formed a closed volume with a certain thickness around the brain. HT and RA plans with four coplanar full arcs (RA4) with half-field technique were generated for the comparison of absolute dose achievable. In total, 30.6 Gy was prescribed as D95% (ie, dose to 95% of PTV volume). Results: In the dosimetric comparison between the two modalities, HT provided more homogenous dose distribution than RA4 (mean HI5−95%: 1.046 vs 1.088, P < .001). The V107% and D2Gy of PTV in HT versus RA4 were 3.06% versus 30.47% and 32.59 Gy versus 33.45 Gy, respectively. HT reduced the Dmean and V5Gy of the brain, brainstem, and hippocampus by 25%–48% and 27%–56% compared with RA4, respectively. Conclusion: Both techniques could provide sufficient coverage for targets, but HT offered more homogenous dose to PTV and lower dose to the central region of the brain involving the brainstem and hippocampus. RA4 could be completed in a shorter time with lower MUs, but with relatively higher dose to the brain or hippocampus. In terms of dosimetry, HT may improve long-term cognitive decline in these young pediatric patients with TDMI.

Assessment of threat arising by closed - volume explosions of fuel - air mixtures

The method of estimation of maximal parameters of combustion of gaseous mixtures in closed space is presented. Estimation of chemical composition of combustion products is based on simplified rules of decomposition of reactive medium. Exemplary calculations of temperature, pressure, heat of combustion of hydrocarbon/air mixtures are presented. The accuracy of presented method was validated by comparison with calculations performed by thermodynamic numerical code that include wide list of chemical substances present in combustion products. The obtained results confirm applicability of the proposed method to predict closed space combustion parameters of gaseous mixtures. Semi-empirical methods of estimation of flammability limits are briefly referred

Numerical simulation of deflagration in hydrogen-air gas mixes

Verification of validity of different manifolds of chemical reactions and coefficients in Arrhenius formulae was made for numerical simulation of deflagration appearing in hydrogen-air gas mixes. Kinetic model of branching chain reaction was tested for initial stage of detonation of this kind of mixes. One dimensional numerical simulations of deflagration initiation where provided for small closed heat isolated region. The next problem was solved numerically:in small closed volume, initially filled by hydrogen-air mix with atmospheric meanings of gas dynamics parameters at moment t=0 temperature rising till meaning, at which reaction of deflagration should begin. Numerical experiment consist of calculation of thermodynamics parameters of gas mix in small isolated volume. Meanings of molar concentration of components of gas mix where calculated by implicit numerical method of Gir for numerical decision. Calculation where provided till zero concentration of hydrogen or not appearing of deflagration at all. Characteristic feature of hydrogen-air gas mix deflagration is appearance of sudden explosion after long period of induction. In this induction period grows of radicals H, O and OH appears. Mass of radicals, nevertheless stay small, and one radical component transverse to the others. This explosion mechanism is branching chain reaction introduced by N.N.Semenov. In agreement with branching chain reaction theory during process of branching chain reaction radicals H, O, OH many times initiates reaction with other components of the mix. Nevertheless mass of radical components preserve small during the reaction, them almost fully disappeared in every time of the process. That’s why method of “quasi - stationary concentration” is treated to components O, OH (velocity of changing of this components concentration is equal to zero). For concentration of component H one simplified differential equation is treated. Speed of changing H essentially grater then speed of changing “slow” components H2, O2, H2O, that’s why equation for H should be solved separately. Algorithm was developed for numerical simulation of hydrogen-air mixes on the basis of theory branching chain reactions. Calculations provided demonstrate applicability of developed algorithm for numerical simulations of initial stage of deflagration of hydrogen-air mixes.

Modeling of the combustion process of methane hydrate taking into account the kinetics of the decomposition process

This paper presents a mathematical model of the combustion process of methane gas hydrate in a closed volume, taking into account the kinetics of its decomposition. The system of basic equations, which includes the equations of conservation of mass (for the entire mixture of gases and each component separately), momentum and energy, is supplemented by the conditions for the balance of mass and heat at the boundary of the phase transition. In this case, the dominant factor determining the intensity of hydrate decomposition is the Arrhenius-type kinetics and conductive heat transfer. Based on the numerical solution of the obtained system of equations based on the method of large particles, the temperature and concentration fields of the system are obtained and analyzed. It is shown that at the initial moment of time, the rate of decomposition of the hydrate according to the model that takes into account the kinetics of the decomposition process is higher than that according to the model that does not take it into account.

EFFECT OF PRESCRIPTION CONFIGURATION ON EXPLOSIVE FORCE NANOTHERMITE COMPOSITION CuO/Al/1Me-3H

Синтезированное в ИПХЭТ СО РАН низкочувствительное высокоэнергетическое вещество 1-метил-3-нитро-1,2,4-триазол (1Ме-3Н) рассматривается как перспективная добавка, способная увеличить силу взрыва нанотермитных композиций. В работе приведены результаты исследования силы взрыва (F) нанотермитной композиции CuO/Al/1Me-3H в зависимости от содержания 1Ме-3Н. Исследован ряд составов различной рецептурной компоновки: I – соотношение компонентов тройной смеси CuO/Al/1Me-3H соответствовало максимальной расчетной теплоте взрыва композиции (Q) при заданном содержании 1Ме-3Н; II – соотношение компонентов тройной смеси соответствовало максимальному расчётному значению давления (P), развиваемому при горении композиции в замкнутом объеме; III –соотношение компонентов базовой нанотермитной пары CuO/Al (79/21 % масс.), соответствующее максимальному расчетному значению Q, оставалось постоянным в тройной смеси; IV – соотношение компонентов базовой нанотермитной пары CuO/Al (76/24 % масс.), соответствующее максимальному расчетному значению P, оставалось постоянным в тройной смеси. Для всех типов компоновки выявлен экстремальный характер зависимости силы взрыва от содержания 1Ме-3Н, при этом максимальные значения F наблюдаются при содержании добавки 5 % для компоновки I (F = 107 %), 10 % для компоновки II (F = 128 %), 25 % для компоновки III (F = 151 %) и 30 % для компоновки IV (F = 147 %). The low-sensitivity high-energy substance 1-methyl-3-nitro-1,2,4-triazole (1Me-3H), synthesized at the IPCET SB RAS, is considered as a promising additive capable of increasing the explosion force of nanotermitic compositions. The paper presents the results of a study of the explosion force (F) of the nanothermic composition CuO / Al / 1Me-3H, depending on the content of 1Me-3H. A number of compositions of various prescription configurations were investigated: I - the ratio of the components of the ternary mixture CuO/Al/1Me-3H corresponded to the maximum calculated heat of explosion of the composition (Q) at a given content of 1Me-3H; II - the ratio of the components of the ternary mixture corresponded to the maximum calculated value of the pressure (P) developed during the combustion of the composition in a closed volume; III — the ratio of the components of the base nanothermite pair CuO/Al (79/21 %), corresponding to the maximum calculated value of Q, remained constant in the ternary mixture; IV - the ratio of the components of the base nanothermite pair CuO / Al (76/24 %), corresponding to the maximum calculated value of P, remained constant in the ternary mixture. For all types of prescription configurations, an extreme nature of the dependence of the force explosion on the content of 1Me-3H was revealed, while the maximum values of F are observed at an additive content of 5% for configuration I (F = 107%), 10% for configuration II (F = 128%), 25% for configuration III (F = 151%) and 30% for configuration IV (F = 147%).

Transfer of "dark hydrogen" by atomic matter. Methods of diagnostics of "dark hydrogen"

This work experimentally shown that traces found on track detectors during the study of low-energy nuclear reactions are also formed in the course of many widely used technical processes (combustion of hydrocarbons, operation of internal combustion engines, physicochemical processes accompanying the process of charging smartphone batteries). This coincidence of the track pattern allows us to consider low-energy nuclear reactions as a significant environmental factor, and indicates the important role of “dark hydrogen” in nature. The paper shows the convective transfer of “dark hydrogen” from the discharge zone along the path of the air-water mixture. Using the theoretical model of “dark hydrogen”, fundamentally new, less laborious, in comparison with track, methods of its registration have been developed and described: 1) measurement of the charge of a copper box with its irradiation with “dark hydrogen”, 2) measurement of pressure in a closed volume when irradiated with “dark hydrogen”, 3) the use of a torsion balance with a nickel plate with magnets when irradiated with “dark hydrogen”.

The Architectonics Features of Heterostructures for IR Range Detectors Based on Polycrystalline Layers of Lead Chalcogenides

A model is developed for the formation of porous intragranular architectonics of nanostructured polycrystalline layers of lead chalcogenides for photodetectors and IR emitters. The layers are obtained under the conditions of thermal evaporation in a quasi-closed volume by the “hot wall” method followed by sensitizing heat treatment in an iodine-containing atmosphere. Model concepts are developed considering the experimental results of studying the intragranular structure of lead chalcogenides through original combined AFM methods over the cross-section of porous grains (cores) encapsulated by an oxide shell (lateral force microscopy and local tunneling I–V spectroscopy).

The Use of Thermovision for Leak Detection in the Automotive Sector

Increasing requirements for environmental protection, safety or reliability force automotive industries to use more efficient tests to measure tightness of the components. Currently adapted methods brings limitations which makes automotive industry open for new techniques for leakage tests. Infrared cameras are widely used in various fields. Using them to test leakage of closed-volume systems allows to significantly reduce test time, especially for objects which requires long stabilization times in competitive methods. In the article thermovision usage for leakage detection of gas springs were described.

Ozone Production with High Voltage in a Mixed Core Mesh Coil

The ozone is a gas composed by three molecules of oxygen which has a great oxidative capacity. This gas can be generated by a nucleus with two electrodes through high voltage in a phenomenon known as corona effect. Actually the conventional nucleus of ozone generators use plane electrodes with a dielectric in the middle of both. A nucleus composed by a mixed ionizador (coil and mesh) is presented as an alternative for an ozone machine in order to take advantage of the individual benefits of each electrode due to its shape and efficiency. A solenoid acts better without dielectric, reducing the consumption, and a mesh improves the air flux. As a result, there is a good production of ozone using this combination of electrodes. However, there are no studies that demonstrate that it is possible to use different types of electrodes in the same ionizador, for this reason in this study will be detected the production of ozone by corona effect in the proposed nucleus and will be approximated its concentration in a closed volume. Keywords: Ozone, corona effect, high voltage, generator, ionization. Resumen El ozono es un gas compuesto por tres moléculas de oxígeno que tiene una gran capacidad oxidativa. Este gas puede ser generado en un núcleo con dos electrodos mediante el uso de altos voltajes en un fenómeno conocido como efecto corona. Actualmente los núcleos de los generadores de ozono convencionales utilizan electrodos planos con un dieléctrico en medio de ellos. Un núcleo compuesto por un ionizador mixto (bobina y malla) se presenta como una alternativa para un ozonificador, con el fin de aprovechar las ventajas individuales de cada electrodo debido a su forma y eficiencia. Un solenoide actúa mejor sin dieléctrico, disminuyendo el consumo, y una malla mejora el flujo de aire. Lo que resulta en una buena producción de ozono utilizando esta combinación de electrodos. Sin embargo, no existen estudios anteriores que demuestran que se puede utilizar diferentes tipos de electrodos en un mismo ionizador, por esta razón en el presente estudio se detectará la producción de ozono por efecto corona en el núcleo mixto propuesto y aproximamos su concentración en un volumen cerrado. Palabras Clave: Ozono, efecto corona, alto voltaje, generador, ionización.