Physical Property and Carbon Black Distribution Impact on Propulsion Efficiency of Paraffin-Based Fuel

2012 ◽  
Author(s):  
Genivaldo P. Santos ◽  
Shirley M. Pedreira ◽  
Pedro T. Lacava
Keyword(s):  
Carbon Black ◽  
Outer Region ◽  
Burning Surface ◽  
Physical Property ◽  
Thin Layers ◽  
Solid Propellants ◽  
Gaseous Oxygen ◽  
Hybrid Propulsion ◽  
Propulsion Efficiency ◽  
Hardness Gradient

In the last decade the hybrid propulsion has been considering as a viable alternative of chemical energy conversion stored in propellants into kinetic energy. This energy is applied in propulsive systems of manned platforms, maneuvering procedures and even in the repositioning process of micro satellites. It is a system of minimum environmental impact and lower cost than traditional systems based on liquid or solid propellants. Paraffin based grains are the hybrid solid fuels appointed as polymeric fuel substitute. The liquid layer formed on the burning surface ensures high regression rate when driven into the flame front. Paraffin grains allow row material recovery and reduce the risk of explosion in the presence of erosive burning. The structure of the grain and the control of the liquefying burning surface layer depend on the additives concentration, such as carbon black, which are added to the fuel matrix during the production process. In the solid propellant paraffin based grain a cylindrical center port developed during the centrifugation tends to concentrate carbon black in the outer region of the grain. During solidification 15% of shrinkage occurs and appears hardness gradient in the longitudinal and transverse directions. The influence of carbon black distribution and hardness gradient in paraffin based grain were evaluated in this work. The study suggests that multiple thin layers grain may generate burning surfaces with hardness and carbon black concentration almost constant. The ballistic properties and propulsion efficiency of a hybrid lab rocket scale with 150 N of thrust were evaluated in the pressure of 2.8 MPa with 140 Kg/(sm2) gaseous oxygen (GOX) mass flux, the results show up the nozzle operation and motor-propellant relationships.

Case study: Seismic resolution and reservoir characterization of thin sands using multiattribute analysis and bandwidth extension in the Daqing field, China

2020 ◽  
Vol 8 (1) ◽  
pp. T89-T102
Author(s):  
David Mora ◽  
John Castagna ◽  
Ramses Meza ◽  
Shumin Chen ◽  
Renqi Jiang
Keyword(s):  
Seismic Data ◽  
Reservoir Characterization ◽  
Statistical Significance ◽  
Physical Property ◽  
Seismic Attributes ◽  
Oil Field ◽  
Thin Layers ◽  
Inversion Method ◽  
Bandwidth Extension ◽  
Multiattribute Analysis

The Daqing field, located in the Songliao Basin in northeastern China, is the largest oil field in China. Most production in the Daqing field comes from seismically thin sand bodies with thicknesses between 1 and 15 m. Thus, it is not usually possible to resolve Daqing reservoirs using only conventional seismic data. We have evaluated the effectiveness of seismic multiattribute analysis of bandwidth extended data in resolving and making inferences about these thin layers. Multiattribute analysis uses statistical methods or neural networks to find relationships between well data and seismic attributes to predict some physical property of the earth. This multiattribute analysis was applied separately to conventional seismic data and seismic data that were spectrally broadened using sparse-layer inversion because this inversion method usually increases the vertical resolution of the seismic. Porosity volumes were generated using target porosity logs and conventional seismic attributes, and isofrequency volumes were obtained by spectral decomposition. The resulting resolution, statistical significance, and accuracy in the determination of layer properties were higher for the predictions made using the spectrally broadened volume.

Aluminum agglomeration involving the second mergence of agglomerates on the solid propellants burning surface: Experiments and modeling

2017 ◽  
Vol 136 ◽  
pp. 219-229 ◽  
Author(s):  
Wen Ao ◽  
Xin Liu ◽  
Hichem Rezaiguia ◽  
Huan Liu ◽  
Zhixin Wang ◽  
...  
Keyword(s):  
Burning Surface ◽  
Solid Propellants

scholarly journals A Numerical Study of Cirrus Bands and Low Static-stability Layers associated with Tropical Cyclone Outflow

2021 ◽  
Author(s):  
Masayuki Kawashima
Keyword(s):  
Numerical Study ◽  
Potential Temperature ◽  
Outer Region ◽  
Static Stability ◽  
Core Region ◽  
Thin Layers ◽  
Vertical Shear ◽  
Thermal Gradients ◽  
Shallow Convection ◽  
The Core

AbstractProminent cirrus cloud banding occurred episodically within a northern cirrus canopy of Typhoon Talim (2017) during its recurvature. The generation mechanisms of the cirrus bands and low static-stability layers that support the bands are investigated using a numerical simulation with the Advanced Research Weather Research and Forecasting Model. Inspection of model output reveals that thin layers of near-neutral to weakly unstable static stability are persistently present in the upper and lower parts of the upper-level outflow, and shallow convection aligned along the vertical shear vector is prevalent in these layers. The cirrus banding occurs as the lowered outflow from the weakening storm ascends slantwise over a midlatitude baroclinic zone, and updrafts of the preexisting shallow convection in the upper part of the outflow layer become saturated. It is shown that the strong outflow resulting from violation of gradient-wind balance in the core region, by itself, creates the low static-stability layers. Analyses of potential temperature and static stability budgets show that the low static-stability layers are created mainly by the differential radial advection of radial thermal gradients on the vertical edges of the outflow. The radial thermal gradients occur in response to the outward air parcel acceleration in the core region and deceleration in the outer region, which, by inducing compensating vertical mass transport into and out of the outflow, act to tilt the isentropes within the shear layers. The effects of environmental flow and cloud radiative forcing on the cirrus banding are also addressed.

scholarly journals Nytrox as “Drop-in” Replacement for Gaseous Oxygen in SmallSat Hybrid Propulsion Systems

Aerospace ◽  
2020 ◽  
Vol 7 (4) ◽  
pp. 43 ◽  
Author(s):  
Stephen A. Whitmore
Keyword(s):  
Specific Impulse ◽  
Acrylonitrile Butadiene Styrene ◽  
N2o Decomposition ◽  
Combustion Efficiency ◽  
Future Research ◽  
Propulsion Systems ◽  
Gaseous Oxygen ◽  
Thrust Coefficient ◽  
Hybrid Propulsion ◽  
Dissolved Carbon

A medical grade nitrous oxide (N2O) and gaseous oxygen (GOX) “Nytrox” blend is investigated as a volumetrically-efficient replacement for GOX in SmallSat-scale hybrid propulsion systems. Combined with 3-D printed acrylonitrile butadiene styrene (ABS), the propellants represent a significantly safer, but superior performing, alternative to environmentally-unsustainable spacecraft propellants like hydrazine. In a manner analogous to the creation of soda-water using dissolved carbon dioxide, Nytrox is created by bubbling GOX under pressure into N2O until the solution reaches saturation. Oxygen in the ullage dilutes N2O vapor and increases the required decomposition energy barrier by several orders of magnitude. Thus, risks associated with inadvertent thermal or catalytic N2O decomposition are virtually eliminated. Preliminary results of a test-and-evaluation campaign are reported. A small spacecraft thruster is first tested using gaseous oxygen and 3-D printed ABS as the baseline propellants. Tests were then repeated using Nytrox as a “drop-in” replacement for GOX. Parameters compared include ignition reliability, latency, initiation energy, thrust coefficient, characteristic velocity, specific impulse, combustion efficiency, and fuel regression rate. Tests demonstrate Nytrox as an effective replacement for GOX, exhibiting a slightly reduced specific impulse, but with significantly higher volumetric efficiency. Vacuum specific impulse exceeding 300 s is reported. Future research topics are recommended.

Ultrasonic borehole velocity imaging

Geophysics ◽  
2006 ◽  
Vol 71 (3) ◽  
pp. F25-F30 ◽  
Author(s):  
Kenneth W. Winkler ◽  
Ralph D’Angelo
Keyword(s):  
High Stress ◽  
Physical Property ◽  
Ultrasonic Waves ◽  
Thin Layers ◽  
Stress Concentrations ◽  
Velocity Image ◽  
Velocity Images ◽  
First Arrival ◽  
A New Technique ◽  
Refracted Waves

We describe a new technique for making high-resolution velocity images of rocks using refracted ultrasonic waves. The use of refracted waves makes this technique potentially suitable for imaging borehole walls. In the laboratory, we use a single-transmitter, two-receiver, first-arrival method for making velocity measurements, with a spatial resolution on the order of [Formula: see text]. Our acoustic pulses are centered near [Formula: see text]. Scans of a borehole wall reveal dipping thin layers and fractures. When external stress is applied perpendicular to the borehole, stress concentrations appear on our images as axial bands of high and low velocities. Breakouts created by high stress also can be imaged. On a planar sample, a velocity image reveals shale laminations and carbonate stringers. For field applications, this technique offers the potential for imaging in both conductive and nonconductive muds and provides images based on a physical property (velocity) that currently is not used for fine-scale borehole imaging.

scholarly journals Cellulose-Based Polymer Composite with Carbon Black for Tetrahydrofuran Sensing

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Susana Hernández-López ◽  
Enrique Vigueras-Santiago ◽  
Miriam Mendoza Mora ◽  
José Rurik Farias Mancilla ◽  
Erasto Armando Zaragoza Contreras
Keyword(s):  
Carbon Black ◽  
Polymer Composite ◽  
Composite Films ◽  
Thin Layers ◽  
Desorption Time ◽  
Multiple Sensing

This work focused on studying the sensing efficiency of tetrahydrofuran (THF) by composite films made of thin layers of a cellulose-based polymer and carbon black. We analyze the reproducibility, durability, desorption time, and the sensitivity percent as a function of the amount of solvent. Two types of experiments were conducted, (1) progressive sensing test (PST) which consisted of progressively increasing the amount of solvent from 0.1 mL increments up to 1.0 mL and (2) multiple sensing test (MST) where the layers were subjected to consecutive pulses of the same amount of solvent, with a minimum of 0.1 mL and a maximum of 0.4 mL. The response and desorption times were a few seconds, and the sensitivity percent ranged from 1% to 170% and was dependent on the solvent quantity.

Interaction between Carbon Black and Polymer in Cured Elastomers

1951 ◽  
Vol 24 (3) ◽  
pp. 597-615
Author(s):  
R. S. Stearns ◽  
B. L. Johnson
Keyword(s):  
Molecular Weight ◽  
Carbon Black ◽  
Chemical Bonding ◽  
Physical Adsorption ◽  
Three Dimensional ◽  
Physical Property ◽  
Carbon Black Particle ◽  
Low Molecular Weight ◽  
Carbon Blacks ◽  
Black Particle

Abstract This research was initiated to determine whether the interaction at the interface between the surface of finely divided solids, such as carbon black, and cured elastomers is primarily physical or chemical in nature. Further, it was desired to correlate some physical property of the reinforced stock with the surface properties of the solid pigment. Through an examination of the thermodynamic changes accompanying the deformation of loaded stocks it is shown that physical adsorption of the van der Waals type occurring at the interface between pigment and polymer is inadequate to account for the experimental observations. However, if chemical bonding occurs at the interface between polymer and pigment, then the entropy of deformation of the stock may be correlated with the extent of this bonding. By a calorimetric method it was demonstrated that the surface of a carbon black particle contains sites that react with bromine to liberate the same amount of heat as low molecular-weight olefins. It is, therefore, proposed that a carbon black particle be considered as a disordered agglomerate of polymeric benzenoid type molecules which contain around their perimeters various functional groups. The existence of olefinic-type unsaturation on the surface of carbon blacks suggests strongly that, in the case of carbon blacks, the polymer and pigment are combined chemically through pigment-sulfur-polymer bonds into a continuous three-dimensional cross-linked matrix.

Solid propellants burning enhancement using foil embedding method

2008 ◽  
Vol 112 (1138) ◽  
pp. 725-732
Author(s):  
H. G. Darabkhanid ◽  
N. S. Mehdizadeh
Keyword(s):  
Burning Rate ◽  
Solid Propellant ◽  
Burning Surface ◽  
New Method ◽  
Published Data ◽  
Solid Propellants ◽  
Embedding Method ◽  
Double Base

Abstract The method of metal embedding is widely employed in solid propellant motors with end-burning configuration, thereby significantly improving the burning rate of the propellants. In this study, the cylindrical foil embedding method is applied to double-base solid propellant, as a new method, and the effects of the type and thickness of the foil on the burning surface, as well as the burning rate, are experimentally investigated. It is shown that by using the foil embedding method, the burning characteristics of solid propellants can be improved. Results have been compared to some available data. To the best of the author’s knowledge there are no published data available on this method.

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