Fluidic proportional thruster for SPARCS 4

Design, development, fabrication, and acceptance test results for two fluidic proportional thrusters for use in SPARCS

Comparison of the Emissions, Noise, and Fuel Consumption Comparison of Direct and Indirect Piezoelectric and Solenoid Injectors in a Low-Compression-Ratio Diesel Engine

An experimental investigation has been carried out to compare the performance and emissions of a low-compression-ratio Euro 5 diesel engine featuring high EGR rates, equipped with dierent injector technologies, i.e., solenoid, indirect-acting, and direct-acting piezoelectric. The comparisons, performed with reference to a state-of-the-art double fuel injection calibration, i.e., pilot-Main (pM), are presented in terms of engine-out exhaust emissions, combustion noise (CN), and fuel consumption, at low–medium engine speeds and loads. The dierences in engine performance and emissions of the solenoidal, indirect-acting, and direct-acting piezoelectric injector setups have been found on the basis of experimental results to mainly depend on the specific features of their hydraulic circuits rather than on the considered injector driving system

Modelling and Motion Analysis of a Cylindrical Steel-Rod under Very Close Distance between Electromagnets with Alternating Polarities

Electromagnetism has many properties and one of it is the electromagnetic force. Based on Coulomb’s Law, forces between electromagnets and forces between permanent magnets, the force is inversely proportional to the distance between one another. Due to this, a prototype is built by a postgraduate student which will be used to study the attraction force and response characteristics between ferrous metal and electromagnets especially at a very close distance. This is because the information for attraction force between ferrous metal and electromagnet under a very close distance is limited. Moreover, the response characteristics is yet to be known towards ferrous metal-rod

The Study Of Ionization In A Military, Heavy-Duty, Diesel Engine

This thesis is an investigation of ionization in a military, heavy-duty, diesel engine. Ionization is a phenomenon which occurs in both spark-ignited and diesel engines. During the reactions of combustion, charged molecules and electrons are produced. The current produced, ion current, from these charges can be measured. The measurement of ion current can serve as an in-cylinder diagnostic for closed-loop engine control strategies. In this work, a literature review was performed to survey previous work as it pertains to ionization in diesel engines. In addition, a detailed description and comparison of the HEUI injection system was made to HPCR. This was done to give a fundamental understanding of the characteristics of the injection system which was employed in the research engine. Lastly, an analysis of experimental data provides insight as to the relationship between ion current and key combustion parameters

Preprototype vapor compression distillation subsystem

A three-person capacity preprototype vapor compression distillation subsystem for recovering potable water from wastewater aboard spacecraft was designed, assembled, and tested. The major components of the subsystem are: (1) a distillation unit which includes a compressor, centrifuge, central shaft, and outer shell; (2) a purge pump; (3) a liquids pump; (4) a post-treat cartridge; (5) a recycle/filter tank; (6) an evaporator high liquid level sensor; and (7) the product water conductivity monitor. A computer based control monitor instrumentation carries out operating mode change sequences, monitors and displays subsystem parameters, maintains intramode controls, and stores and displays fault detection information. The mechanical hardware occupies 0.467 m3, requires 171 W of electrical power, and has a dry weight of 143 kg. The subsystem recovers potable water at a rate of 1.59 kg/hr, which is equivalent to a duty cycle of approximately 30% for a crew of three. The product water has no foul taste or odor. Continued development of the subsystem is recommended for reclaiming water for human consumption as well as for flash evaporator heat rejection, urinal flushing, washing, and other on-board water requirements

Miniature reciprocating heat pumps and engines

The present invention discloses a miniature thermodynamic device that can be constructed using standard micro-fabrication techniques. The device can be used to provide cooling, generate power, compress gases, pump fluids and reduce pressure below ambient (operate as a vacuum pump). Embodiments of the invention relating to the production of a cooling effect and the generation of electrical power, change the thermodynamic state of the system by extracting energy from a pressurized fluid. Energy extraction is attained using an expansion process, which is as nearly isentropic as possible for the appropriately chosen fluid. An isentropic expansion occurs when a compressed gas does work to expand, and in the disclosed embodiments, the gas does work by overcoming either an electrostatic or a magnetic force

Retention and application of Skylab experiences to future programs

The problems encountered and special techniques and procedures developed on the Skylab program are described along with the experiences and practical benefits obtained for dissemination and use on future programs. Three major topics are discussed: electrical problems, mechanical problems, and special techniques. Special techniques and procedures are identified that were either developed or refined during the Skylab program. These techniques and procedures came from all manufacturing and test phases of the Skylab program and include both flight and GSE items from component level to sophisticated spaceflight systems

On the rate of injection modeling applied to direct injection compression ignition engines

Modern engine design has challenging requirements towards maximum power output, fuel consumption and emissions. For engine combustion development programs, the injection system has to be able to operate reliable under a variety of operating conditions. Today s legislations for quieter and cleaner engines require multiple injection strategies, where it is important to understand the behavior of the system and to measure the effect of one injection on subsequent injections. This study presents a methodology for 0D modeling the mass flow rate and the rail pressure of a common rail system, constructed from a set of experimental measurements in engine-like operating conditions, for single and multiple injection strategies. The model is based in mathematical expressions and correlations that can simulate the mass flow rate obtained with the Bosch tube experiment, focusing on the shape and the injected mass, using few inputs: rail pressure, back pressure, energizing time, etc. The model target is to satisfy two conditions: lowest computational cost and to reproduce the realistic injected quantity. Also, the influence of the rail pressure level on the start of injection is determined, especially for multiple injection strategies on the rate shape and injected mass. Good accuracy was obtained in the simulations. Results showed that the model error is within the 5%, which corresponds at the same time to the natural error of the injector and to the accuracy of the measures which had been done. The benefits of the model are that simulations can be performed quickly and easily for any operation points, and on the other hand that the model can be used in real-time on the engine test bench for mass estimations when doing additional experiments or calibration activities.The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work was sponsored by "Ministerio de Economia y Competitividad'' in the frame of the project "Estudio de la interaccion chorropared en condiciones realistas de motor (SPRAY WALL)'' reference TRA2015-67679-c2-1-R.Payri Marín, R.; Gimeno García, J.; Novella Rosa, R.; Bracho León, GC. (2016). On the rate of injection modeling applied to direct injection compression ignition engines. International Journal of Engine Research. 17(10):1015-1030. doi:10.1177/1468087416636281S10151030171