Opening injection pressure as a part of multimodal monitoring to detect intraneural injections

Background: The impulse for the propulsion of a rocket engine is obtained from the combustion of propellant mixture inside the combustion chamber and as the plume exhausts through a convergent- divergent nozzle. At stoichiometric ratio, the temperature inside the combustion chamber can be as high as 3500K. Thus, effective cooling of the thrust chamber becomes an essential criterion while designing a rocket engine. Objective: A new cooling method of thrust chambers was introduced by Chiaverni, which is termed as Vortex Combustion Cold-Wall Chamber (VCCW). The patent works on cyclone separators and confined vortex flow mechanism for providing high propellant mixing with improved degree of turbulence inside the combustion chamber, providing the required notion for studies on VCCW. The flow inside a VCCW has a complex structure characterised by axial pressure losses, swirl velocities, centrifugal force, flow reversal and strong turbulence. In order to study the flow phenomenon, both the experimental and numerical investigations are carried out. Methods: In this study, non-reactive flow analysis was conducted with real propellants like gaseous oxygen and hydrogen. The test was conducted to analyse the influence of mixture ratio and injection pressure of the propellants on the chamber pressure in a vortex combustion chamber. A vortex combustor was designed in which the oxidiser injected tangentially at the aft end near the nozzle spiraled up to the top plate and formed an inner core inside the chamber. The fuel was injected radially from injectors provided near the top plate and the propellants were mixed in the inner core. This resulted in enhanced mixing and increased residence time for the fuel. More information on the flow behaviour has been obtained by numerical analysis in Fluent. The test also investigated the sensitivity of the tangential injection pressure on the chamber pressure development. Results: All the test cases showed an increase in chamber pressure with the mixture ratio and injection pressure of the propellants. The maximum chamber pressure was found to be 3.8 bar at PC1 and 2.7 bar at PC2 when oxidiser to fuel ratio was 6.87. There was a reduction in chamber pressure of 1.1 bar and 0.7 bar at PC1 and PC2, respectively, in both the cases when hydrogen was injected. A small variation in the pressure of the propellant injected tangentially made a pronounced effect on the chamber pressure and hence vortex combustion chamber was found to be very sensitive to the tangential injection pressure. Conclusion: VCCW mechanism has been to be found to be very effective for keeping the chamber surface within the permissible limit and also reducing the payload of the space vehicle.

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Multimodal monitoring (MMM) in the perioperative period

Signa Vitae - A Journal In Intensive Care And Emergency Medicine ◽

10.22514/sv112.062016.3 ◽

2016 ◽

Vol 11 (S2) ◽

pp. 22

Keyword(s):

Perioperative Period ◽

Multimodal Monitoring

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Study on high-temperature wear and mechanism of Al-Si/graphite composites prepared by the die-casting process

Industrial Lubrication and Tribology ◽

10.1108/ilt-10-2019-0454 ◽

2020 ◽

Vol 72 (10) ◽

pp. 1153-1158 ◽

Cited By ~ 1

Author(s):

Yafei Deng ◽

Xiaotao Pan ◽

Guoxun Zeng ◽

Jie Liu ◽

Sinong Xiao ◽

...

Keyword(s):

Friction Coefficient ◽

Wear Rate ◽

Peer Review ◽

Die Casting ◽

Casting Machine ◽

Injection Pressure ◽

Casting Process ◽

Matrix Alloy ◽

Content Type ◽

The Matrix

Purpose This paper aims to improve the tribological properties of aluminum alloys and reduce their wear rate. Design/methodology/approach Carbon is placed in the model at room temperature, pour 680°C of molten aluminum into the pressure chamber, and then pressed it into the mold containing carbon felt through a die casting machine, and waited for it to cool, which used an injection pressure of 52.8 MPa and held the same pressure for 15 s. Findings The result indicated that the mechanical properties of matrix and composite are similar, and the compressive strength of the composite is only 95% of the matrix alloy. However, the composite showed a low friction coefficient, the friction coefficient of Gr/Al composite is only 0.15, which just is two-third than that of the matrix alloy. Similarly, the wear rate of the composite is less than 4% of the matrix. In addition, the composite can avoid severe wear before 200°C, but the matrix alloy only 100°C. Originality/value This material has excellent friction properties and is able to maintain this excellent performance at high temperatures. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-10-2019-0454/

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Investigation on degradation mechanism of polymer blockages in unconsolidated sandstone reservoirs

e-Polymers ◽

10.1515/epoly-2020-0006 ◽

2020 ◽

Vol 20 (1) ◽

pp. 55-60

Author(s):

Wenting Dong ◽

Dong Zhang ◽

Keliang Wang ◽

Yue Qiu

Keyword(s):

Oil Recovery ◽

Degradation Mechanism ◽

Injection Pressure ◽

Polymer Flooding ◽

Core Flooding ◽

Reservoir Properties ◽

Thermal Analyzer ◽

Sandstone Reservoirs ◽

Suction Index ◽

Weighing Method

AbstractPolymer flooding technology has shown satisfactorily acceptable performance in improving oil recovery from unconsolidated sandstone reservoirs. The adsorption of the polymer in the pore leads to the increase of injection pressure and the decrease of suction index, which affects the effect of polymer flooding. In this article, the water and oil content of polymer blockages, which are taken from Bohai Oilfield, are measured by weighing method. In addition, the synchronous thermal analyzer and Fourier transform infrared spectroscopy (FTIR) are used to evaluate the composition and functional groups of the blockage, respectively. Then the core flooding experiments are also utilized to assess the effect of polymer plugs on reservoir properties and optimize the best degradant formulation. The results of this investigation show that the polymer adsorption in core after polymer flooding is 0.0068 g, which results in a permeability damage rate of 74.8%. The degradation ability of the agent consisting of 1% oxidizer SA-HB and 10% HCl is the best, the viscosity of the system decreases from 501.7 to 468.5 mPa‧s.

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Numerical investigation of injection parameters and piston bowl geometries on emission and thermal performance of DI diesel engine

SN Applied Sciences ◽

10.1007/s42452-021-04633-1 ◽

2021 ◽

Vol 3 (6) ◽

Author(s):

Ikhtedar Husain Rizvi ◽

Rajesh Gupta

Keyword(s):

Diesel Engine ◽

Thermal Performance ◽

Equivalence Ratio ◽

Fuel Injection ◽

Injection Pressure ◽

Injection Nozzle ◽

Piston Bowl ◽

Injection Parameters ◽

Nozzle Size ◽

Engine Emission

AbstractTightening noose on engine emission norms compelled manufacturers globally to design engines with low emission specially NOx and soot without compromising their performance. Amongst various parameters, shape of piston bowls, injection pressure and nozzle diameter are known to have significant influence over the thermal performance and emission emanating from the engine. This paper investigates the combined effect of fuel injection parameters such as pressure at which fuel is injected and the injection nozzle size along with shape of piston bowl on engine emission and performance. Numerical simulation is carried out using one cylinder naturally aspirated diesel engine using AVL FIRE commercial code. Three geometries of piston bowls with different tumble and swirl characteristics are considered while maintaining the volume of piston bowl, compression ratio, engine speed and fuel injected mass constant along with equal number of variations for injection nozzle size and pressures for this analysis. The investigation corroborates that high swirl and large turbulence kinetic energy (TKE) are crucial for better combustion. TKE and equivalence ratio also increased as the injection pressure increases during the injection period, hence, enhances combustion and reduces soot formation. Increase in nozzle diameter produces higher TKE and equivalence ratio, while CO and soot emission are found to be decreasing and NOx formation to be increasing. Further, optimization is carried out for twenty-seven cases created by combining fuel injection parameters and piston bowl geometries. The case D2H1P1 (H1 = 0.2 mm, P1 = 200 bar) found to be an optimum case because of its lowest emission level with slightly better performance.

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Optimization of Fuel Injection Parameters of Moringa oleifera Biodiesel-Diesel Blend for Engine-Out-Responses Improvements

Symmetry ◽

10.3390/sym13060982 ◽

2021 ◽

Vol 13 (6) ◽

pp. 982

Author(s):

Yew Heng Teoh ◽

Heoy Geok How ◽

Farooq Sher ◽

Thanh Danh Le ◽

Hwai Chyuan Ong ◽

...

Keyword(s):

Diesel Engines ◽

Fossil Fuels ◽

Moringa Oleifera ◽

Fuel Injection ◽

Injection Pressure ◽

Single Step ◽

Rapid Decline ◽

Fuel Blend ◽

Combustion Dynamics ◽

Rsm Optimization

Biodiesel has gained popularity in diesel engines as a result of the rapid decline of fossil fuels and population growth. The processing of biodiesel from non-edible Moringa Oleifera was investigated using a single-step transesterification technique. Both fuels had their key physicochemical properties measured and investigated. In a common-rail diesel engine, the effects of MB50 fuel blend on the symmetric characteristics of engine-out responses were evaluated under five load settings and at 1000 rpm. As compared to standard diesel, MB50 increased brake thermal efficiency (BTE), and nitrogen oxides (NOx) emissions while lowering brake specific fuel consumption (BSFC), and smoke emissions for all engine loads. A further study of injection pressure and start of injection (SOI) timing for MB50 fuel was optimized using response surface methodology (RSM). The RSM optimization resulted in improved combustion dynamics due to symmetry operating parameters, resulting in a simultaneous decrease in NOx and smoke emissions without sacrificing BTE. RSM is an efficient optimization method for achieving optimal fuel injection parameter settings, as can be deduced. As a result, a clearer understanding of the use of MB50 fuel in diesel engines can be given, allowing for the best possible engine efficiency.

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