Material Removal by High-Pressure Liquid Jets at Ten Kilobars

1975 ◽  
Vol 97 (3) ◽  
pp. 1067-1073
Author(s):  
K. F. Neusen ◽  
E. C. LaBrush
Keyword(s):  
High Pressure ◽  
Material Removal ◽  
High Pressures ◽  
Solid Material ◽  
High Energy ◽  
High Energy Density ◽  
Liquid Jets ◽  
System Pressure ◽  
Series Of Experiments ◽  
Nozzle Inlet

High-energy-density jets (0.75 × 106 hp/in.2) resulting from expanding liquid at extremely high pressures are capable of removing solid material from a wide variety of targets. Liquid jets with velocities up to 4000 fps (1220 mps) resulting from 10 kilobars of system pressure were used to penetrate aluminum, steel, rock, and plastic targets. A series of experiments was conducted to determine the effectiveness of materials removal as a function of nozzle-to-target distance and nozzle inlet pressure.

High-pressure new phase of AgN3

2021 ◽  
pp. 2150386
Author(s):  
Shifeng Niu ◽  
Ran Liu ◽  
Xuhan Shi ◽  
Zhen Yao ◽  
Bingbing Liu ◽  
...  
Keyword(s):  
High Pressure ◽  
Energy Density ◽  
Density Functional ◽  
High Energy ◽  
High Energy Density ◽  
Detonation Properties ◽  
Ambient Conditions ◽  
Structure Search ◽  
Enthalpy Difference ◽  
High Energy Density Material

The structural evolutionary behaviors of AgN3 have been studied by using the particle swarm optimization structure search method combined with the density functional theory. One stable high-pressure metal polymeric phase with the [Formula: see text] space group is suggested. The enthalpy difference analysis indicates that the Ibam-AgN3 phase will transfer to the I4/mcm-AgN3 phase at 4.7 GPa and then to the [Formula: see text]-AgN3 phase at 24 GPa. The [Formula: see text]-AgN3 structure is composed of armchair–antiarmchair N-chain, in which all the N atoms are sp2 hybridization. The inherent stability of the armchair–antiarmchair chain and the anion–cation interaction between the N-chain and Ag atom induce a high stability of the [Formula: see text]-AgN3 phase, which can be captured at ambient conditions and hold its stable structure up to 1400 K. The exhibited high energy density (1.88 KJ/g) and prominent detonation properties ([Formula: see text] Km/s; [Formula: see text] GPa) of the [Formula: see text]-AgN3 phase make it a potentially high energy density material.

Highly Efficient Conversion of Ammonia in Electricity by Solid Oxide Fuel Cells

2006 ◽  
Vol 3 (4) ◽  
pp. 499-502 ◽  
Author(s):  
N. J. J. Dekker ◽  
G. Rietveld
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Energy Density ◽  
High Pressures ◽  
Cell Voltage ◽  
Electrical Current ◽  
High Energy ◽  
Solid Oxide ◽  
High Energy Density ◽  
Oxide Fuel

Hydrogen is the fuel for fuel cells with the highest cell voltage. A drawback for the use of hydrogen is the low energy density storage capacity, even at high pressures. Liquid fuels such as gasoline and methanol have a high energy density but lead to the emission of the greenhouse gas CO2. Ammonia could be the ideal bridge fuel, having a high energy density at relative low pressure and no (local) CO2 emission. Ammonia as a fuel for the solid oxide fuel cell (SOFC) appears to be very attractive, as shown by cell tests with electrolyte supported cells (ESC) as well as anode supported cells (ASC) with an active area of 81cm2. The cell voltage was measured as function of the electrical current, temperature, gas composition and ammonia (NH3) flow. With NH3 as fuel, electrical cell efficiencies up to 70% (LHV) can be achieved at 0.35A∕cm2 and 60% (LHV) at 0.6A∕cm2. The cell degradation during 3000 h of operation was comparable with H2 fueled measurements. Due to the high temperature and the catalytic active Ni∕YSZ anode, NH3 cracks at the anode into H2 and N2 with a conversion of >99.996%. The high NH3 conversion is partly due to the withdrawal of H2 by the electrochemical cell reaction. The remaining NH3 will be converted in the afterburner of the system. The NOx outlet concentration of the fuel cell is low, typically <0.5ppm at temperatures below 950°C and around 4ppm at 1000°C. A SOFC system fueled with ammonia is relative simple compared with a carbon containing fuel, since no humidification of the fuel is necessary. Moreover, the endothermic ammonia cracking reaction consumes part of the heat produced by the fuel cell, by which less cathode cooling air is required compared with H2 fueled systems. Therefore, the system for a NH3 fueled SOFC will have relatively low parasitic power losses and relative small heat exchangers for preheating the cathode air flow.

scholarly journals Production of sub-gigabar pressures by a hyper-velocity impact in the collider using laser-induced cavity pressure acceleration

2017 ◽  
Vol 35 (4) ◽  
pp. 619-630
Author(s):  
J. Badziak ◽  
M. Kucharik ◽  
R. Liska
Keyword(s):  
Energy Conversion ◽  
Conversion Efficiency ◽  
Inertial Confinement Fusion ◽  
High Pressures ◽  
Strong Shock ◽  
Energy Conversion Efficiency ◽  
High Energy ◽  
High Energy Density ◽  
Cavity Pressure ◽  
Shock Energy

AbstractProduction of high dynamic pressure using a strong shock wave is a topic of high relevance for high-energy-density physics, inertial confinement fusion, and materials science. Although the pressures in the multi-Mbar range can be produced by the shocks generated with a large variety of methods, the higher pressures, in the sub-Gbar or Gbar range, are achievable only with nuclear explosions or laser-driven shocks. However, the laser-to-shock energy conversion efficiency in the laser-based methods currently applied is low and, as a result, multi-kJ multi-beam lasers have to be used to produce such extremely high pressures. In this paper, the generation of high-pressure shocks in the newly proposed collider in which the projectile impacting a solid target is driven by the laser-induced cavity pressure acceleration (LICPA) mechanism is investigated using two-dimensional hydrodynamic simulations. A special attention is paid to the dependence of shock parameters and the laser-to-shock energy conversion efficiency on the impacted target material and the laser driver energy. It has been found that both in case of low-density and high-density solid targets, the shock pressures in the sub-Gbar range can be produced in the LICPA-based collider with the laser energy of only a few hundreds of joules, and the laser-to-shock energy conversion efficiency can reach values of 10–20%, by an order of magnitude higher than the conversion efficiencies achieved with other laser-based methods used so far.

scholarly journals Synthesis of magnesium-nitrogen salts of polynitrogen anions

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Dominique Laniel ◽  
Bjoern Winkler ◽  
Egor Koemets ◽  
Timofey Fedotenko ◽  
Maxim Bykov ◽  
...  
Keyword(s):  
High Pressures ◽  
Molecular Nitrogen ◽  
High Energy ◽  
High Energy Density ◽  
Ambient Conditions ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Energy Density Materials ◽  
Polynitrogen Compounds ◽  
Laser Heated

Abstract The synthesis of polynitrogen compounds is of fundamental importance due to their potential as environmentally-friendly high energy density materials. Attesting to the intrinsic difficulties related to their formation, only three polynitrogen ions, bulk stabilized as salts, are known. Here, magnesium and molecular nitrogen are compressed to about 50 GPa and laser-heated, producing two chemically simple salts of polynitrogen anions, MgN4 and Mg2N4. Single-crystal X-ray diffraction reveals infinite anionic polythiazyl-like 1D N-N chains in the crystal structure of MgN4 and cis-tetranitrogen N44− units in the two isosymmetric polymorphs of Mg2N4. The cis-tetranitrogen units are found to be recoverable at atmospheric pressure. Our results respond to the quest for polynitrogen entities stable at ambient conditions, reveal the potential of employing high pressures in their synthesis and enrich the nitrogen chemistry through the discovery of other nitrogen species, which provides further possibilities to design improved polynitrogen arrangements.

scholarly journals N2H: a novel polymeric hydronitrogen as a high energy density material

2015 ◽  
Vol 3 (8) ◽  
pp. 4188-4194 ◽  
Author(s):  
Ketao Yin ◽  
Yanchao Wang ◽  
Hanyu Liu ◽  
Feng Peng ◽  
Lijun Zhang
Keyword(s):  
Energy Density ◽  
First Principles ◽  
High Pressures ◽  
High Energy ◽  
High Energy Density ◽  
Structure Search ◽  
High Energy Density Material

Based on the first-principles structure search methodology, a hitherto unknown stable polymeric N2H phase is discovered at high pressures.

Phase Transition and Chemical Reactivity of 1H-tetrazole under High Pressure up to 100 GPa

2021 ◽  
Author(s):  
Dexiang Gao ◽  
Xingyu Tang ◽  
Xuan Wang ◽  
Xin Yang ◽  
Peijie Zhang ◽  
...  
Keyword(s):  
Phase Transition ◽  
High Pressure ◽  
Energy Density ◽  
Chemical Reactivity ◽  
High Energy ◽  
High Energy Density ◽  
High Energy Density Materials

Pressure-induced phase transition and polymerization of nitrogen-rich molecules are widely focused due to its extreme importance for the development of green high energy density materials. Here, we present a study...

scholarly journals Hydrodynamics of the leucon sponge pump

2019 ◽  
Vol 16 (150) ◽  
pp. 20180630 ◽  
Author(s):  
Seyed Saeed Asadzadeh ◽  
Poul S. Larsen ◽  
Hans Ulrik Riisgård ◽  
Jens H. Walther
Keyword(s):  
High Pressure ◽  
High Pressures ◽  
Pressure Rise ◽  
Pump Efficiency ◽  
Pressure Losses ◽  
Positive Displacement ◽  
System Pressure ◽  
Flow Through ◽  
Mechanical Pump ◽  
Pumping Units

Leuconoid sponges are filter-feeders with a complex system of branching inhalant and exhalant canals leading to and from the close-packed choanocyte chambers. Each of these choanocyte chambers holds many choanocytes that act as pumping units delivering the relatively high pressure rise needed to overcome the system pressure losses in canals and constrictions. Here, we test the hypothesis that, in order to deliver the high pressures observed, each choanocyte operates as a leaky, positive displacement-type pump owing to the interaction between its beating flagellar vane and the collar, open at the base for inflow but sealed above. The leaking backflow is caused by small gaps between the vaned flagellum and the collar. The choanocyte pumps act in parallel, each delivering the same high pressure, because low-pressure and high-pressure zones in the choanocyte chamber are separated by a seal (secondary reticulum). A simple analytical model is derived for the pump characteristic, and by imposing an estimated system characteristic we obtain the back-pressure characteristic that shows good agreement with available experimental data. Computational fluid dynamics is used to verify a simple model for the dependence of leak flow through gaps in a conceptual collar–vane–flagellum system and then applied to models of a choanocyte tailored to the parameters of the freshwater demosponge Spongilla lacustris to study its flows in detail. It is found that both the impermeable glycocalyx mesh covering the upper part of the collar and the secondary reticulum are indispensable features for the choanocyte pump to deliver the observed high pressures. Finally, the mechanical pump power expended by the beating flagellum is compared with the useful (reversible) pumping power received by the water flow to arrive at a typical mechanical pump efficiency of about 70%.

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