Propeller aerodynamic optimisation to minimise energy consumption for electric fixed-wing aircraft

2021 ◽  
pp. 1-27
Author(s):  
J.D. Hoyos ◽  
J.P. Alvarado ◽  
J.H. Jiménez
Keyword(s):  
Electric Propulsion ◽  
Three Dimensional ◽  
Operational Parameters ◽  
Vortex Theory ◽  
Performance Predictions ◽  
Wide Range ◽  
Optimal Value ◽  
Reynolds Number Effects ◽  
Study Case ◽  
The University

Abstract An electric propulsion model for propeller-driven aircraft is developed with the aim of minimising the power consumption for a given airspeed and thrust. Blade Element Momentum Theory (BEMT) is employed for propeller performance predictions fed with aerodynamic aerofoil data obtained from a proposed combined Computational Fluid Dynamics (CFD)–Montgomerie method, which is also validated. The Two-Dimensional (2D) aerofoil data are corrected to consider compressibility, three-dimensional, viscous and Reynolds-number effects. The BEMT model showed adequate fitting with experimental data from the University of Illinois Urbana Champaign (UIUC) database. Additionally, Goldstein optimisation via vortex theory is employed to design pitch and chord distributions minimising the induced losses of the propeller. Particle swarm optimisation is employed to find the optimal value for a wide range of geometrical and operational parameters considering some constraints. The optimisation algorithm is validated through a study case where an existing optimisation problem is approached, leading to very similar results. Some trends and insights are obtained from the study case and discussed regarding the design of an optimal propulsion system. Finally, CFD simulations of the study case are carried out, showing a slight relative error of BEMT.

scholarly journals Representing the War. Early Twentieth Century Maps and Models in the Fonds of the Italian War History Museum in Rovereto

2021 ◽  
Vol 4 ◽  
pp. 1-8
Author(s):  
Elena Dai Prà ◽  
Valentina De Santi ◽  
Giannantonio Scaglione
Keyword(s):  
Twentieth Century ◽  
Three Dimensional ◽  
Field Surveys ◽  
History Museum ◽  
Early Twentieth Century ◽  
Wide Range ◽  
The First World War ◽  
Three Dimensional Models ◽  
The University ◽  
First World

Abstract. The representation of the areas in which some of the most significant events of the First World War took place has produced a wide range of materials, such as cartography, aerial and terrestrial photos, textual descriptions and field surveys. In addition, war events were also represented through three-dimensional models. Topographic maps and models constitute composite figurations, which are rich in informative data useful for the preservation of the memory of places and for increasing the knowledge of cultural heritage. Hence, these sources need to be studied, described, interpreted and used for future enhancement. The focus of this paper are archival materials from the collections kept at the Italian War History Museum of Rovereto (Museo Storico Italiano della Guerra), in the Trentino-Alto Adige region. Firstly, we will investigate the cartographic fond in order to assess the composition and origin of its materials. Secondly, we will present the Museum’s collection of Early-Twentieth Century models. Such precious heritage is not yet part of an exhibition, and is kept in the Museum’s warehouses. The paper constitutes the occasion to present the initial results of a still ongoing project by the Geo-Cartographic Centre for Study and Documentation (GeCo) of the University of Trento on the study and analysis of two archival complexes preserved in the abovementioned Museum. In particular, the paper focuses on the heuristic value of such representational devices, which enable an analysis of the different methods and languages through which space is planned and designed, emphasizing the complementarity between different types of visualization.

scholarly journals Kinematic and Polarimetric Radar Observations of the 10 May 2010, Moore–Choctaw, Oklahoma, Tornadic Debris Signature

2017 ◽  
Vol 145 (7) ◽  
pp. 2723-2741 ◽  
Author(s):  
Casey B. Griffin ◽  
David J. Bodine ◽  
Robert D. Palmer
Keyword(s):  
Three Dimensional ◽  
Dielectric Constants ◽  
Oklahoma City ◽  
Polarimetric Radar ◽  
Wind Fields ◽  
Irregular Shapes ◽  
Wide Range ◽  
Wind Retrievals ◽  
The University ◽  
Differential Reflectivity

Tornadoes are capable of lofting large pieces of debris that present irregular shapes, near-random orientations, and a wide range of dielectric constants to polarimetric radars. The unique polarimetric signature associated with lofted debris is called the tornadic debris signature (TDS). While ties between TDS characteristics and tornado- and storm-scale kinematic processes have been speculated upon or investigated using photogrammetry and single-Doppler analyses, little work has been done to document the three-dimensional wind field associated with the TDS. Data collected by the Oklahoma City, Oklahoma (KTLX), and Norman, Oklahoma (KOUN), WSR-88D S-band radars as well as the University of Oklahoma’s (OU) Advanced Radar Research Center’s Polarimetric Radar for Innovations in Meteorology and Engineering (OU-PRIME) C-band radar are used to construct single- and dual-Doppler analyses of a tornadic supercell that produced an EF4 tornado near the towns of Moore and Choctaw, Oklahoma, on 10 May 2010. This study documents the spatial distribution of polarimetric radar variables and how each variable relates to kinematic fields such as vertical velocity and vertical vorticity. Special consideration is given to polarimetric signatures associated with subvortices within the tornado. An observation of negative differential reflectivity ([Formula: see text]) at the periphery of tornado subvortices is presented and discussed. Finally, dual-Doppler wind retrievals are compared to single-Doppler axisymmetric wind fields to illustrate the merits of each method.

Edward Battersby Bailey, 1881-1965

1965 ◽  
Vol 11 ◽  
pp. 1-21 ◽  
Keyword(s):  
United Kingdom ◽  
Great Britain ◽  
Three Dimensional ◽  
Geological Survey ◽  
Metamorphic Rocks ◽  
Surface Mapping ◽  
Major Work ◽  
The United Kingdom ◽  
Wide Range ◽  
The University

Edward Battersby Bailey was a former Director of the Geological Survey of Great Britain and the Museum of Practical Geology, also for a time Professor of Geology in the University of Glasgow. He was born on 1 July 1881 and died on 19 March 1965, having dedicated his life to geological thinking and exposition. Though his studies extended beyond the confines of the United Kingdom and over a wide range of geology, his major work was interpretation, into three-dimensional concepts, of the phenomena observed by surface mapping of mainly igneous and metamorphic rocks in the mountains, hills and islands of western Scotland. His work was marked by physical and mental fearlessness and enthusiasm, reinforced by a flair or instinct for arriving at a novel explanation of his own or others’ observations.

TEM study of boron additions to cobalt aluminide

1988 ◽  
Vol 46 ◽  
pp. 546-547
Author(s):  
Gerald B. Feldewerth
Keyword(s):  
High Temperature ◽  
Turbine Engines ◽  
Major Drawback ◽  
University Of Missouri ◽  
Specific Strength ◽  
Aerospace Applications ◽  
Wide Range ◽  
Ordered Alloys ◽  
The University ◽  
Very High

In recent years an increasing emphasis has been placed on the study of high temperature intermetallic compounds for possible aerospace applications. One group of interest is the B2 aiuminides. This group of intermetaliics has a very high melting temperature, good high temperature, and excellent specific strength. These qualities make it a candidate for applications such as turbine engines. The B2 aiuminides exist over a wide range of compositions and also have a large solubility for third element substitutional additions, which may allow alloying additions to overcome their major drawback, their brittle nature.One B2 aluminide currently being studied is cobalt aluminide. Optical microscopy of CoAl alloys produced at the University of Missouri-Rolla showed a dramatic decrease in the grain size which affects the yield strength and flow stress of long range ordered alloys, and a change in the grain shape with the addition of 0.5 % boron.

Electron sources: Past, present, and future

1993 ◽  
Vol 51 ◽  
pp. 764-765
Author(s):  
David C Joy
Keyword(s):  
Glass Tube ◽  
Source Size ◽  
Electron Gun ◽  
Operating Parameters ◽  
Operational Parameters ◽  
Electron Sources ◽  
Difficult Decision ◽  
Probe Size ◽  
Wide Range ◽  
Overall Performance

The electron source is the most important component of the Scanning electron microscope (SEM) since it is this which will determine the overall performance of the machine. The gun performance can be described in terms of quantities such as its brightness, its source size, its energy spread, and its stability and, depending on the chosen application, any of these factors may be the most significant one. The task of the electron gun in an SEM is, in fact, particularly difficult because of the very wide range of operational parameters that may be required e.g a variation in probe size of from a few angstroms to a few microns, and a probe current which may go from less than a pico-amp to more than a microamp. This wide range of operating parameters makes the choice of the optimum source for scanning microscopy a difficult decision.Historically, the first step up from the sealed glass tube ‘cathode ray generator’ was the simple, diode, tungsten thermionic emitter.

Biodiversity in Vegetation and Ecosystems»: symposium on the occasion of the retirement of Prof. Dr. Fred J.A. Daniels (Munster, Germany, July 11, 2008)

2008 ◽  
pp. 123-124
Author(s):  
N. V. Matveyeva
Keyword(s):  
Wide Range ◽  
65Th Anniversary ◽  
The University

July 2008 in Münster (Germany) hosted a Symposium on the occasion of the 65th anniversary of Professor of the University of this city, Fred Daniels (Frederikus Josephus Alphonsus Daniëls). The title of this Symposium «Biodiversity in Vegetation and Ecosystems» reflected the wide range of interests of the celebrant.

Tassos Papacostas and Maria Parani (eds.), Discipuli dona ferentes. Glimpses of Byzantium in Honour of Marlia Mundell Mango. Β υζ ά ν τ ι ο ς. Studies in Byzantine History and Civilization 11. Turnhout: Brepols Publishers, 2017. XXX, 486, 111 b/w figures.

Mediaevistik ◽  
2020 ◽  
Vol 32 (1) ◽  
pp. 333-337
Author(s):  
Natalia Teteriatnikov
Keyword(s):  
Late Antiquity ◽  
Oxford University ◽  
Present Volume ◽  
Wide Range ◽  
Byzantine Period ◽  
The University ◽  
Vast Territory ◽  
Byzantine History

The present volume is a tribute to Marlia Mango on the occasion of her retirement from the University service of Kings College, Oxford University. All essays, written by her students, offer the result of their research and express a profound gratitude to their teacher. The essays tackle a wide range of subjects covering a vast territory from Constantinople to its periphery as well as Italy. Chronologically diverse, research materials span from late antiquity to the late Byzantine period.

scholarly journals Nitrogen-Doped Graphene Iron-Based Particle Electrode Outperforms Activated Carbon in Three-Dimensional Electrochemical Water Treatment Systems

Water ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3121
Author(s):  
Hosna Ghanbarlou ◽  
Nikoline Loklindt Pedersen ◽  
Morten Enggrob Simonsen ◽  
Jens Muff
Keyword(s):  
Activated Carbon ◽  
Three Dimensional ◽  
Cell Voltage ◽  
Reduction Reaction ◽  
Process Data ◽  
Nitrogen Doped ◽  
Pesticide Removal ◽  
Optimal Value ◽  
Nitrogen Doped Graphene ◽  
Doped Graphene

The synergy between electrochemical oxidation and adsorption on particle electrodes was investigated in three-dimensional (3D) systems for p-nitrosodimethylaniline (RNO) decolorization and pesticide removal. A comparison was made between granular activated carbon (GAC) and a novel synthesized nitrogen-doped graphene-based particle electrode (NCPE). Experiments on RNO decolorization show that the synergy parameter of the 3D-NCPE system was improved 3000 times compared to the studied 3D-GAC system. This was due to the specific nanostructure and composition of the NCPE material. Nitrogen-doped graphene triggered an oxygen reduction reaction, producing hydrogen peroxide that simultaneously catalyzed on iron sites of the NCPEs to hydroxyl radicals following the electro-Fenton (EF) process. Data showed that in the experimental setup used for the study, the applied cell voltage required for the optimal value of the synergy parameter could be lowered to 5V in the 3D-NCPEs process, which is significantly better than the 15–20 V needed for synergy to be found in the 3D-GAC process. Compared to previous studies with 3D-GAC, the removal of pesticides 2,6 dichlorobenzamide (BAM), 2-methyl-4-chlorophenoxyaceticacid (MCPA), and methylchlorophenoxypropionic acid (MCPP) was also enhanced in the 3D-NCPE system.

Turbulent three-dimensional dielectric electrohydrodynamic convection between two plates

2012 ◽  
Vol 696 ◽  
pp. 228-262 ◽  
Author(s):  
A. Kourmatzis ◽  
J. S. Shrimpton
Keyword(s):  
Spatial Data ◽  
Three Dimensional ◽  
Reynolds Numbers ◽  
Two Dimensions ◽  
Three Dimensions ◽  
Energy Budgets ◽  
Turbulent Regime ◽  
Scalar Flux ◽  
Wide Range ◽  
Scalar Variance

AbstractThe fundamental mechanisms responsible for the creation of electrohydrodynamically driven roll structures in free electroconvection between two plates are analysed with reference to traditional Rayleigh–Bénard convection (RBC). Previously available knowledge limited to two dimensions is extended to three-dimensions, and a wide range of electric Reynolds numbers is analysed, extending into a fully inherently three-dimensional turbulent regime. Results reveal that structures appearing in three-dimensional electrohydrodynamics (EHD) are similar to those observed for RBC, and while two-dimensional EHD results bear some similarities with the three-dimensional results there are distinct differences. Analysis of two-point correlations and integral length scales show that full three-dimensional electroconvection is more chaotic than in two dimensions and this is also noted by qualitatively observing the roll structures that arise for both low (${\mathit{Re}}_{E} = 1$) and high electric Reynolds numbers (up to ${\mathit{Re}}_{E} = 120$). Furthermore, calculations of mean profiles and second-order moments along with energy budgets and spectra have examined the validity of neglecting the fluctuating electric field ${ E}_{i}^{\ensuremath{\prime} } $ in the Reynolds-averaged EHD equations and provide insight into the generation and transport mechanisms of turbulent EHD. Spectral and spatial data clearly indicate how fluctuating energy is transferred from electrical to hydrodynamic forms, on moving through the domain away from the charging electrode. It is shown that ${ E}_{i}^{\ensuremath{\prime} } $ is not negligible close to the walls and terms acting as sources and sinks in the turbulent kinetic energy, turbulent scalar flux and turbulent scalar variance equations are examined. Profiles of hydrodynamic terms in the budgets resemble those in the literature for RBC; however there are terms specific to EHD that are significant, indicating that the transfer of energy in EHD is also attributed to further electrodynamic terms and a strong coupling exists between the charge flux and variance, due to the ionic drift term.

A comparative study and combined application of RSM and ANN in adsorptive removal of diuron using biomass ashes

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Sunil K. Deokar ◽  
Nachiket A. Gokhale ◽  
Sachin A. Mandavgane
Keyword(s):  
Three Dimensional ◽  
Current Approach ◽  
Coefficient Of Determination ◽  
Ann Model ◽  
Operational Parameters ◽  
Initial Concentration ◽  
Combined Application ◽  
Artificial Neural Network Ann ◽  
Relationship Of ◽  
Biomass Ashes

Abstract Biomass ashes like rice husk ash (RHA), bagasse fly ash (BFA), were used for aqueous phase removal of a pesticide, diuron. Response surface methodology (RSM) and artificial neural network (ANN) were successfully applied to estimate and optimize the conditions for the maximum diuron adsorption using biomass ashes. The effect of operational parameters such as initial concentration (10–30 mg/L); contact time (0.93–16.07 h) and adsorbent dosage (20–308 mg) on adsorption were studied using central composite design (CCD) matrix. Same design was also employed to gain a training set for ANN. The maximum diuron removal of 88.95 and 99.78% was obtained at initial concentration of 15 mg/L, time of 12 h, RHA dosage of 250 mg and at initial concentration of 14 mg/L, time of 13 h, BFA dosage of 60 mg respectively. Estimation of coefficient of determination (R 2) and mean errors obtained for ANN and RSM (R 2 RHA = 0.976, R 2 BFA = 0.943) proved ANN (R 2 RHA = 0.997, R 2 BFA = 0.982) fits better. By employing RSM coupled with ANN model, the qualitative and quantitative activity relationship of experimental data was visualized in three dimensional spaces. The current approach will be instrumental in providing quick preliminary estimations in process and product development.

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