Aerospace2014, 1(3), 101-136; doi:10.3390/aerospace1030101 (registering DOI) - published 19 December 2014 Show/Hide Abstract
Abstract: Improvements in safety in the air and in space can be achieved through better ergonomics, better work environment, and other efforts of the traditional avionic psychology that directly affect human behaviors and performance. There is also a significant potential, however, for further reduction in aerospace accidents and casualties through better understanding the role that various uncertainties play in the planner’s and operator’s worlds of work, when never-perfect human, never failure-free navigation equipment and instrumentation, never hundred-percent-predictable response of the object of control (air- or space-craft), and uncertain-and-often-harsh environments contribute jointly to the likelihood of a mishap. By employing quantifiable and measurable ways of assessing the role and significance of such uncertainties and treating a human-in-the-loop (HITL) as a part, often the most crucial part, of a complex man–instrumentation–equipment–vehicle–environment system, one could improve dramatically the state-of-the-art in assuring aerospace operational safety. This can be done by predicting, quantifying and, if necessary, even specifying an adequate (low enough) probability of a possible accident. Nothing and nobody is perfect, of course, and the difference between a highly reliable object, product, performance or a mission and an insufficiently reliable one is “merely” in the level of the never-zero probability of failure. Application of the probabilistic predictive modeling (PPM) concept provides a natural and an effective means for reduction of vehicular casualties. When success and safety are imperative, ability to predict and quantify the outcome of an HITL related mission or a situation is a must. This is not the current practice though. The application of the PPM concept can improve therefore the state-of-the-art in understanding and accounting for the human performance in a vehicular mission or a situation. While the traditional statistical human-factor-oriented approaches are based on experimentations followed by statistical analyses, the PPM concept is based on, and starts with, physically meaningful and flexible predictive modeling followed by highly focused and highly cost effective experimentations geared to the chosen governing model(s). The PPT concept enables one to quantify, on the probabilistic basis, the outcome of a particular HITL related effort, situation or a mission. If the predicted outcome, in terms of the most likely probability of the operational failure, is not favorable, then an appropriate sensitivity analysis (SA) based on the developed and available algorithms can be effectively conducted to improve the situation. With the appropriate modifications and generalizations, such a cost-effective and insightful approach is applicable to numerous, not even necessarily in the aerospace and vehicular domain, HITL related missions and situations, when a human encounters an uncertain environment or a hazardous off-normal situation. The suggested approach is applicable also when there is an incentive to quantify human’s qualifications and performance, and/or when there is a need to assess and possibly improve his/her role in a particular mission or a situation. The general PPM concepts are illustrated in this analysis by addressing several more or less typical aerospace HITL related problems and by providing meaningful numerical examples.
Abstract: The investigation of aviation alternative fuels has increased significantly in recent years in an effort to reduce the environment and climate impact by aviation industry. Special requirements have to be met for qualifying as a suitable aviation fuel. The fuel has to be high in energy content per unit of mass and volume, thermally stable and avoiding freezing at low temperatures. There are also many other special requirements on viscosity, ignition properties and compatibility with the typical aviation materials. There are quite a few contending alternative fuels which can be derived from coal, natural gas and biomass.[...]
Abstract: Recent advances in smart structures and multifunctional materials have facilitated many novel aerospace technologies such as morphing aircraft. A morphing aircraft, bio-inspired by natural fliers, has gained a lot of interest as a potential technology to meet the ambitious goals of the Advisory Council for Aeronautics Research in Europe (ACARE) Vision 2020 and the FlightPath 2050 documents. A morphing aircraft continuously adjusts its wing geometry to enhance flight performance, control authority, and multi-mission capability.[...]
Abstract: Welcome to Aerospace, an open journal covering aerospace science, engineering and technology. We seek to publish theoretical, fundamental, and applied results linked to potential applications related to research, design, manufacture, operations, control and maintenance of aircraft and spacecraft. A full description of the journal scope can be found on the journal website .[...]
Abstract: A large number of theoretical and experimental studies have shown that the performance of kerosene combustion increases significantly if combustion is being assisted by the addition of hydrogen to the fuel/air mixture during the combustion process. It reduces the amount of CO, CO2 and NOx emissions, while increasing the flame stability limits. It also helps in bruning fuel/air mixtures at much leaner equivalence ratios. The same principle could be applied to gain benefits in gas turbine combustors. Hydrogen for this purpose could be produced by the reforming of hydrocarbon fuels using a reformer module. This paper presents key hydrogen reforming technologies which, by implementation in gas turbine combustors, hold potential for improving both their performance and service life.
Abstract: The rapid growth of the aviation sector around the globe has witnessed an overwhelming impact on fossil fuel resources. With the implementation of stricter environmental laws over emissions by conventional jet fuels, growing demand for research on alternative fuels has become imperative. One-hundred percent Synthetic Paraffinic Kerosene (SPK) and Fully Formulated Synthetic Jet Fuel have surfaced as viable alternatives for gas turbine engines due to their similar properties as that of Jet Fuel. This paper presents results from an experimental study performed on a small gas turbine engine, comparing emissions performance and vibrations for conventional Jet A-1 Fuel, thermally stressed 100% SPK and Fully Formulated Synthetic Jet Fuel. Different vibration frequencies, power spectra were observed for different fuels. Gaseous emissions observed were nearly the same, whereas, significant changes in particulates emissions were observed.