Investigation of Gelled JP-8 and RP-1 Fuels
Richard Arnold ∗ , Paulo H. S. Santos † , Travis Kubal ‡ , Osvaldo Campanella § , William E. Anderson ¶
Abstract —For future airbreathing and rocket pro- pulsion systems gelled propellants can be a promising replacement for conventional propellants. Especially for rocket engines, the application of a gelled fuel and gelled oxidizer can combine the advantages of con- ventional solid and liquid propellants without taking into account the speciﬁc disadvantages of both indi- vidual systems. The present publication describes the rheological behavior of gelled JP-8 turbine fuel and gelled rocket propellant RP-1, whereas fumed silica as a gelling agent has been used. Alongside the determi- nation of an optimal mixing process, the rheological parameters of the investigated gelled hydrocarbon fu- els showed a signiﬁcant inﬂuence of the added amount of silica in comparison to the ungelled pure liquids.
CHAPTER 6: CONCLUSIONS
This chapter provides a summary of the main results based on the experimental investigation, along with conclusions derived from the results. The limitations and future recommendations related of work are also discussed. Initially, the engine test results at the medium load using diesel, n-butanol, and ethanol-diesel are discussed to demonstrate the exhaust conditions suitable for the long breathing LNT operation. Then the LNT regeneration tests are performed under engine exhaust like conditions on an offline after- treatment test bench. To fulfill the objective of the after-treatment tests, the alcohol fuels such as ethanol and n-butanol are used as a reductant, for the LNT regeneration. In the end, the combined LNT-SCR after-treatment system is tested using n-butanol as a reductant for the LNT regeneration. The conclusion based on the experimental investigations are summarized below:
Current jet fuel specification requires 8%-25% (v/v) aromatic content to guarantee a promising sealing performance of polymer materials which is also specified based on experience. As the usage of alternative fuels should not cause any change to current engine structure, research need to be done to understand their interaction and impact on the seals. Previous tests focused on comparing the differences of changes in physical properties of these sealing materials, such as mass, volume, and hardness, etc. Such tests are referred as ‘static’ tests, which mean polymer sheets, or O-ring samples, are immerged in certain amount of fuel samples and left for a period of time. Measurements are then carried out at certain time intervals to compare how these properties change during this process. The advantage of this method is the data of physical property changes of the seals, especially volume, can be obtained from various alternative fuels. Then by comparing these data with that from current jet fuel, e.g. Jet A/Jet A-1, different impacts of the fuels on those properties can be seen.
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1.3 Scope and objectives of this work
Following the motivation and literature review above, a number of persisting challenges were identified. Firstly, there is still need for improved understanding of the parametric dependence of laser-induced optical breakdown on focusing optics, thermodynamic conditions, and gas type. Secondly, the division of available absorbed energy for ignition after optical breakdown has only been studied in air. The ultimate goal of laser ignition studies is to obtain ignition models. In order to have accurate models of laser ignition, parametric dependencies must also be investigated for combustible mixtures. Thirdly, new diagnostics could be introduced to better understand the thermodynamic conditions and plasma kernel structure immediately after breakdown. This would allow for more rigorous validation of laser ignition simulations apart from the usual temporal evolution of the laser-induced shock wave front. Further, we need to understand the flame quenching behavior of laser-ignited flames under lean conditions since this can affect power output and emissions in combustion systems. Another deficiency in laser ignition literature is characterization of fuel structure and chemical composition effects on successful ignition. Finally, these characteristics of laser ignition are better appreciated by comparing them with characteristics of spark ignition. Resolving these questions can provide greater prediction and control capabilities for laser ignition systems. This thesis seeks to contribute to the resolution of these outstanding questions. Specifically, this work seeks to:
b Mechanical Engineering, University of Southern Queensland, Toowoomba, 4350 QLD, Australia, Tel.; +61 746311373, E-mail address: firstname.lastname@example.org
A comprehensive study on the methanol as an alternative fuel has been carried out. A four stroke four cylinder diesel engine was adopted to study engine power, torque, break specific fuel consumption, break thermal efficiency and exhaust temperature with the fuel of fraction methanol in diesel. In this study, the diesel engine was tested using methanol blended with diesel at certain mixing ratio of 10:90, 20:80 and 30:70 of methanol to diesel respectively. The performance of the engine using blended fuel compared to the performance of engine with diesel fuel. Experimental results showed that the output power and torque for diesel fuel is lower compared to methanol-diesel blended fuel at any ratio. The best mixing ratio that produced the lowest exhaust temperature was at 10% of Methanol in 90% of Diesel fuel. The exhaust temperature for diesel fuel was higher compared to any mixing of the blended fuel. The brake specific fuel consumption for the three mixing ratios was not varying significantly but the lowest was for 30% Methanol and 70% Diesel. The specific fuel consumption for diesel fuel was much lower compared to any mixing ratio. It was noticed that brake thermal efficiency was thus improved in almost all operation conditions with the methanol and diesel blended fuels.
Start of fuel injection and fuel type are two important factors affecting engine performance and exhaust emissions in internal combustion engines. In the present study, a one-dimensional computational fluid dynamics solution with GT-Power software is used to simulate a six-cylinder diesel engine to study the performance and exhaust emissions with different injection timing and alternative fuels. Starting the fuel injection was from 10 °CA BTDC to the TDC with an interval between two units and from alternative fuel bases (diesel), including methanol, ethanol, diesel, and ethanol compounds, biodiesel and decane was used. To validate the model, a comparison is made between simulation data and experimental data (including torque and power) showing the validation error is less than 6.12% and indicating the software model validation. Also, the modeling results show that decane fuel has higher brake power and brake torque of more than 6.10 % while fuel is injected at 10 °CA BTDC compared to the base fuel, and illustrates a reduction of 5.75 % in specific fuel consumption due to producing higher power. In addition, with the advance of injection timing compared to baseline, the amount of CO and HC in biodiesel fuel reduces to 83.88% and 64.87%, respectively, and the lowest NOX emission with the retardation of starting injection, to decane fuel is awarded. In general, the results show that decane fuel could be a good alternative to diesel fuel in diesel engines when it starts fuel injection at 10 °CA BTDC.
(25, 50, 100 and 150) ppm are prepared. These nanoparticles are blended with diesel fuel in varying volume fraction by the means of an electric mixer and an ultrasonicator (JTS-1018). Their stability characteristics were analyzed under static conditions. The Nano fuels are (DF+Al 2 O 3 ) and (DF+TiO 2 ). The study shows that the addition of
This means that the balance between these two important parameters (fuel viscosity and oxidizer mass flow) decides whether the vaporization or the entrainment regression rate plays a more important role. In this way it is also possible to explain the trend of the flame height for the two fuels. Pure paraffin 6805 has a lower viscosity and experiences the entrainment phenomenon at every oxidizer mass flows (see Fig. 13,14). According to Karabeyoglu et al.  and the Kelvin-Helmholtz instability theory , the instabilities and, thus, the droplets entrainment increase as the mass flux increases (in this case the mass flux and flow have the same trend, since the area is almost a constant). Also the vaporization regression rate increases with the oxidizer mass flux, but with a slower slope. In the case of the pure paraffin, it is possible to say that the droplets entrainment dominates direct gasification. When the viscosity is really low, the vaporization from the liquid surface is negligible, meaning that all of the mass is transferred to the gas flow in form of droplets . This brings to an important increase in the regression rate, which can be also see in our burning tests (see Fig. 15), and to a decrease in the liquid layer thickness (see Karabeyoglu et al. ). Consequently, also the flame height tends to decrease, since the flame position is strictly connected to the regression rate. For what concerns the fuel with the higher viscosity, no entrainment arises at very low mass flows (10-20 g/s). Therefore, the regression rate is given only from the liquid fuel vaporization and pyrolization. As the oxidizer mass flow increases, the liquid layer becomes unstable, due to the higher shear stresses, and droplets entrainment takes place, thus bringing to a higher regression rate. However, the fuel liquid viscosity is higher than that of the pure paraffin, so the melt layer is less unstable and fewer droplets are able to be entrained in the flow. This means that, in this case, the vaporization regression rate plays still an important role even at high mass flows. Therefore, the evaporation blowing of the gaseous phase mass transfer from the fuel surface is still pretty high. This “pushes” the flame sheet further away from the liquid layer and, consequently, increases the flame height.
This means that the overall efficiency of the process will be different. In this article, two possible scenarios have been investigated in order to assess the potential to directly replace conventional jet fuel – kerosene with methyl buthanoate – MB (a short chain fatty acid methyl ester – repre- senting biofuel) and a synthetic jet fuel (Fischer–Tropsch fuel) using computational fluid dynam- ics (CFD) modelling in a typical modern air-spray combustor. A detailed comparison of kerosene with alternative fuel performance has been made. In addition, the impact of fuel blending on the combustion performance has been investigated. The CFD results indicate that there are notable differences in the engine performance and emissions when replacing conventional jet fuel with alternative fuels. The effect of alternative fuel chemistry on the combustion characteristics is noticeable both in the flamelet calculation and the CFD main flow field computations. This is particularly the case for MB.
The majority of the test runs were made with the amount of hydrogen as the variable. At each load, the amount of biodiesel and Hydrogen are varied so as to run the engine at constant speed. The Hydrogen supply is limited by Rotometer capacity. Then the engine is brought to table operating conditions and the readings are noted for different loads. In addition, the injection and combustion of both fuels is possible in the same cycle. For studying the engine process with the mixture of both diesel and hydrogen, the engine is brought to stable operating conditions on diesel alone with the injection pump controls set for the fuel quantity desired. The hydrogen flow is started and the amount used was controlled by adjusting the supply valve. The hydrogen gas is stored in standard commercial at about 200 bar compressed gas cylinder.
This central aim was achieved through a numerical simulation study based on a validated finite element model for predicting dynamic responses of cylinder liners in an IC engine, with consideration of the characteristics of structural modes and nonlinearities of assembly constraints. The findings about relationship between combustion of alternative fuels and the liner vibrations raised in FE model have been confirmed through a series of experimental researches based on a single-cylinder engine test bench. Moreover, the FE model also presented the dynamic deformations of liner surface, which offers the possibility to study the influence of liner deformations to friction behaviours. Based on these dynamic deformations, a dynamic deformation based model of film formation and distribution between the piston rings and liners was developed to take into consideration of potential influences from liner dynamic distortions. Both the minimum oil film thickness and friction forces were found to be sensitive to the dynamic characteristics of liners determined by operating conditions and fuel types. To further investigate the possibility of friction reduction induced by external vibration excitations, a preliminary experimental study has been conducted based on a motoring test bench.
2.3. Electrochemical testing
For testing purposes, each single cell was sealed between a 4 cm OD and 2 cm ID alumina tube and an alumina washer with the same dimensions using a mica ring and Aremco Ceramabond®
cement, with the anode side bonded within the tube. The cell was filled with the powdered anodic mixture until it occupied approximately two-thirds of the volume of the alumina tube. The sealed fuel cell was placed into the fuel-cell test stand and heated to 650°C while flowing preheated argon (30 sccm) and air (50 sccm) to the anode and cathode chambers, respectively. The electrochemical testing for the biomass fuels was performed at 650, 800, and 750°C (in this specific order) while for carbon black and coal the order was 650, 700, 750, and 800°C. The temperature of the cell was measured on the anode side by a type-K thermocouple placed a few millimeters above the carbon/carbonate mixture. A cross-section of the testing set up can be found in a previous paper . Silver mesh and wire were attached to the cathode and anode surface with LSCF ink and Pt ink, respectively, for current collection. The cells were electrochemically characterized using a galvanostat/potentiostat (Solartron 1287A, Solartron Analytical, England). The voltage-current-power (V-I-P) plots were constructed by applying a current load to the cell that increased in a stepwise fashion at 2 mA/s, and proceeded until the cell voltage reached 0 V. After electrochemical testing, the cell was cooled in argon to room temperature for further observation.
As discussed at the beginning of this section, the pure GTL fuel and GTL blended fuels did not bring down the combustion temperature and did not bring down the air joined in fuel combustion. Thus, the reason contributing to the improvement in NO X emissions
from GTL blended fuels should be something in local scale mixing and chemical compositions. Therefore, it’s important to recall the discussion from the fuel property section provided at the beginning of this chapter. The main difference between GTL fuel and diesel fuel is that GTL fuel consisted of almost all straight chains and branched alkanes, indicating the GTL fuel is more easily to be burned off. This is due to the aromatics in diesel fuel are unsaturated chain, which provide low hydrogen and high carbon content. In contrast to aromatics, the straight chains and branched alkanes in GTL fuel has lower carbon content. [Garner, 2009]. Therefore, the GTL is more easily to be combusted completely when compared to diesel. The TGA results in figure 5-1 proved that the GTL fuel is lighter than diesel fuel, i.e. have more lighter fractions. This explains why the pure GTL fuel had slightly lower NO X emissions than diesel fuel
1 National Research Tomsk Polytechnic University, 634050 Tomsk, Russia
Abstract. The processes of heat and mass transfer were investigated experimentally while moving and evaporating the atomized water flow in high-temperature combustion products of typical liquid fuels and organic flammable liquids: gasoline, kerosene, acetone, crude oil, industrial alcohol. We determined typical periods of liquid extinguishing by an atomized water flow of various dispersability. Data of the discharge of extinguishing medium corresponding to various parameters of atomization and duration of using the atomization devices was presented. It is shown that U m ≈3.5 m/s is a minimal outflow velocity of droplets during moving while passing the distance of 1m in the high- temperature gas medium to stop the combustion of organic liquids.
Solar distillation system works on the simple principle of evaporation and condensation process .Unlike other types of distillation system which works either by consuming electrical energy or by burning fossil fuels; it works simply on thermal energy provided by the sun which is free in nature. The hot waste brackish water is cogenerated. It takes brackish or impure water as an input to the system and clean wateras well as hot brackish water as an output. The simplicity of the system makes it ideal for disaster situations mainly flood, where the water is plenty but unsafe to drink .Test run on the performance
The asymmetric structure caused a large flux difference as the hot feed passing through the lumen compared to the shell side. This phenomenon was analysed by considering the heat and mass balance across each layer, from which it was found that the skin layer combining with the exponential relation between the interface temperature and vapour pressure lead to the difference. VEDCMD was also tested with this module. In the experiments, the cold stream was drawn through the module on the shell side, and the degree of vacuum was increased by increasing the stream velocity. It was found that the global mass transfer coefficient increased as negative pressure was applied on the cold side under the same hydrodynamic and thermal conditions. For a comparison test with positive pressure for the cold flow, a maximum global mass transfer coefficient was also found when only the cold stream velocity increased, due to the skin layer effect. In this case, the flux was reduced dramatically by swapping the feed stream from inside the fibre to outside the fibre, due to the change of heat conduction and mass transfer sequence. Therefore, based on this study, it is important to consider both the heat and mass transfers in fabrication of MD membranes.
(n) (in respect of products of subheadings 2710 1951 t o 2710 1967 only) atmospheric distillation, on condition that less than 30 % of these products distils, by volume, including losses, at 300 °C by the ISO 3405 method (equivalent to the ASTM D 86 method). If 30 % or more by volume, including losses, of such products distils at 300 °C by the ISO 3405 method (equivalent to the ASTM D 86 method), the quantities of products which may be obtained during the atmospheric distillation and which fall in subheadings 2710 1211to 2710 1290 or 2710 1911 to 2710 1929 shall be dutiable at the same rates as those provided for under subheadings 2710 1962 t o 2710 1967 according to the kind and value of the products used and on the net weight of the products obtained. This rule shall not apply to products so obtained which, within a period of six months and subject to such other conditions as may be determined by the competent authorities, are to undergo a specific process or chemical transformation by a process not being a specific process;
[Notfn. No. 38/04-CE., dt. 4.8.2004]
Exemptions petroleum oils and oils obtained from bituminous minerals, crude, from whole of the National Calamity Contingent Duty under specified conditions.
In exercise of the powers conferred by sub-section (1) of section 5A of the Central Excise Act 1944 (1 of 1944), read with section 136 of the Finance Act, 2001 (14 of 2001), the Central Government being satisfied that it is necessary in the public interest so to do, hereby exampts, petroleum oils and oils obtained from bituminous minerals, crude, produced either in the fields under the Production Sharing Contracts, specified in colomn (2) of the Table below or in the exploration blocks offered under the New Exploration Licensing Policy (NELP) through competitive international bidding, from the whole of the National Calam- ity Contingent Duty leviable thereon under section 136 of the said Finance Act 2001, read with section 169 of the Finance Act, 2003 (32 of 2003).
In this study, for the first time, the performance of different types of batch distillation arrangements were determined in terms of minimum operation batch time under single and two-control intervals operations for the synthesis of methyl propionate via the esterification reaction of propionic acid and methanol. Control variables (i.e. reflux ratio and/or feed rate) were employed as a piecewise-constant, which were next discretised utilizing CVP algorithm. An optimization problem was formulated including the process model within gPROMS modelling tool. The product quantity and its concentration were used as operational constraints. Observation results employing single-control policy (for DF-SBD) and feed rate (for CBD and SF- SBD) showed that DF-SBD was more appropriate than both CBD and SF-SBD processes in terms of minimum operating time, and maximum product quality.