Analytics of turbomachine geometry

Abstract: For any type of reaction turbomachine, the blade geometry has the same topology and can be modeled by a single mathematical representation. This canonical representation of a blade has been implemented in the Beltrami workbench (BW) which is fully integrated into the FreeCAD modeler. The result is a geometric representation embedded in FreeCAD that allows the blade to be considered as a parametric object that can be analyzed and modified. Before any complex fluid simulation, analysis of the parametric representation of the blade profile can be useful to detect any deviation from healthy fluid behavior. This analysis can be carried out during the design but in addition, it can be carried out on an existing blade parameterized by a reverse engineering process. One effect of the use in the design of such a tool is to control the angular deviation of the fluid in a progressive manner by avoiding successions of accelerations-decelerations which are not desirable and could cause losses, cavitation, vibes. This can result in a significant gain in performance and reliability.Résumé de la communication présentée lors du congrès international tenu conjointement par Canadian Society for Mechanical Engineering (CSME) et Computational Fluid Dynamics Society of Canada (CFD Canada), à l’Université de Sherbrooke (Québec), du 28 au 31 mai 2023

Engineering Dynamics and Life Sciences

From Preface: This is the fourteenth time when the conference “Dynamical Systems: Theory and Applications” gathers a numerous group of outstanding scientists and engineers, who deal with widely understood problems of theoretical and applied dynamics. Organization of the conference would not have been possible without a great effort of the staff of the Department of Automation, Biomechanics and Mechatronics. The patronage over the conference has been taken by the Committee of Mechanics of the Polish Academy of Sciences and Ministry of Science and Higher Education of Poland. It is a great pleasure that our invitation has been accepted by recording in the history of our conference number of people, including good colleagues and friends as well as a large group of researchers and scientists, who decided to participate in the conference for the first time. With proud and satisfaction we welcomed over 180 persons from 31 countries all over the world. They decided to share the results of their research and many years experiences in a discipline of dynamical systems by submitting many very interesting papers. This year, the DSTA Conference Proceedings were split into three volumes entitled “Dynamical Systems” with respective subtitles: Vibration, Control and Stability of Dynamical Systems; Mathematical and Numerical Aspects of Dynamical System Analysis and Engineering Dynamics and Life Sciences. Additionally, there will be also published two volumes of Springer Proceedings in Mathematics and Statistics entitled “Dynamical Systems in Theoretical Perspective” and “Dynamical Systems in Applications”

Bibliography of Lewis Research Center technical publications announced in 1984

This compilation of abstracts describes and indexes the technical reporting that resulted from the scientific and engineering work performed and managed by the Lewis Research Center in 1984. All the publications were announced in the 1984 issues of STAR (Scientific and Technical Aerospace Reports) and/or IAA (International Aerospace Abstracts). Included are research reports, journal articles, conference presentations, patents and patent applications, and theses

Energy: A continuing bibliography with indexes, issue 40, January 1984

This bibliography lists 775 reports, articles and other documents introduced into the NASA scientific and technical information system from October 1, 1983 through December 31, 1983

Vulnerability of Electric Power Systems to Volcanic Ashfall Hazards

Volcanic eruptions are powerful natural events which impact strongly on society. As human populations grow and expand into volcanically active areas, their exposure and vulnerability to volcanic hazards is also increasing. Of all volcanic hazards, ashfall is the most likely to impact lifelines because of the large areas affected. The widespread dispersal of ash can cause large-scale disruption of vital infrastructure services, aviation, and primary production. Electric power supply is arguably the most crucial of modern infrastructure systems, especially considering the dependence of other sectors on electricity to maintain functionality. During and immediately after ashfalls, electric power systems are vulnerable to a number of impacts, but disruption from volcanic ash-induced insulator flashover (unintended, disruptive electrical discharge) is most common. This thesis investigates the vulnerability of electric power systems to volcanic ashfall by examining impacts to the different sectors of the modern power system and exploring appropriate mitigation strategies. Analogue laboratory trials using a pseudo (synthetic) ash are undertaken to verify the environmental, volcanological and electrical parameters that most affect electrical conductivity and therefore the flashover mechanism in these experiments. While dry ash is highly resistant to the flow of electric current, increasing moisture content, soluble salt load, and compaction (bulk density) will reduce this resistance and, in turn, increase the potential for flashover. Volcanic ash is an acute form of airborne pollution for areas downwind of active volcanoes. Results from laboratory experiments in this thesis suggest that insulator pollution (volcanic ash) performance (dielectric strength) is primarily dictated by (1) the conductivity of the ash, and (2) insulator material, profile (shape) and dimensioning. Composite polymer insulators tested herein effectively minimise sinusoidal leakage current and partial discharge activity and also exhibit higher pollution performance when compared to ceramic equivalents. Irrespective of insulator material, however, the likelihood of flashover increases significantly once the bottom surface of suspension insulator watersheds become contaminated in wet ash. The thesis investigates the vulnerability (hazard intensity/damage ratio) of electric power systems to volcanic ashfall hazards. Identification, analysis, and reduction of the risk of ashfall impacts to power networks is explored as a part of holistic volcanic risk assessment. The findings of the thesis contribute to the readiness, response and recovery protocols for large electric power systems in volcanic disasters; which directly affects the functional operation and economics of industrial and commercial society

Friction Force Microscopy of Deep Drawing Made Surfaces

Aim of this paper is to contribute to micro-tribology understanding and friction in micro-scale interpretation in case of metal beverage production, particularly the deep drawing process of cans. In order to bridging the gap between engineering and trial-and-error principles, an experimental AFM-based micro-tribological approach is adopted. For that purpose, the can’s surfaces are imaged with atomic force microscopy (AFM) and the frictional force signal is measured with frictional force microscopy (FFM). In both techniques, the sample surface is scanned with a stylus attached to a cantilever. Vertical motion of the cantilever is recorded in AFM and horizontal motion is recorded in FFM. The presented work evaluates friction over a micro-scale on various samples gathered from cylindrical, bottom and round parts of cans, made of same the material but with different deep drawing process parameters. The main idea is to link the experimental observation with the manufacturing process. Results presented here can advance the knowledge in order to comprehend the tribological phenomena at the contact scales, too small for conventional tribology