Introduction Why Study Marine Hydrodynamics?
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Che 253M Experiment No. 2 COMPRESSIBLE GAS FLOW
Rev. 8/15 AD/GW ChE 253M Experiment No. 2 COMPRESSIBLE GAS FLOW The objective of this experiment is to familiarize the student with methods for measurement of compressible gas flow and to study gas flow under subsonic and supersonic flow conditions. The experiment is divided into three distinct parts: (1) Calibration and determination of the critical pressure ratio for a critical flow nozzle under supersonic flow conditions (2) Calculation of the discharge coefficient and Reynolds number for an orifice under subsonic (non- choked) flow conditions and (3) Determination of the orifice constants and mass discharge from a pressurized tank in a dynamic bleed down experiment under (choked) flow conditions. The experimental set up consists of a 100 psig air source branched into two manifolds: the first used for parts (1) and (2) and the second for part (3). The first manifold contains a critical flow nozzle, a NIST-calibrated in-line digital mass flow meter, and an orifice meter, all connected in series with copper piping. The second manifold contains a strain-gauge pressure transducer and a stainless steel tank, which can be pressurized and subsequently bled via a number of attached orifices. A number of NIST-calibrated digital hand held manometers are also used for measuring pressure in all 3 parts of this experiment. Assorted pressure regulators, manual valves, and pressure gauges are present on both manifolds and you are expected to familiarize yourself with the process flow, and know how to operate them to carry out the experiment. A process flow diagram plus handouts outlining the theory of operation of these devices are attached. -
Laws of Similarity in Fluid Mechanics 21
Laws of similarity in fluid mechanics B. Weigand1 & V. Simon2 1Institut für Thermodynamik der Luft- und Raumfahrt (ITLR), Universität Stuttgart, Germany. 2Isringhausen GmbH & Co KG, Lemgo, Germany. Abstract All processes, in nature as well as in technical systems, can be described by fundamental equations—the conservation equations. These equations can be derived using conservation princi- ples and have to be solved for the situation under consideration. This can be done without explicitly investigating the dimensions of the quantities involved. However, an important consideration in all equations used in fluid mechanics and thermodynamics is dimensional homogeneity. One can use the idea of dimensional consistency in order to group variables together into dimensionless parameters which are less numerous than the original variables. This method is known as dimen- sional analysis. This paper starts with a discussion on dimensions and about the pi theorem of Buckingham. This theorem relates the number of quantities with dimensions to the number of dimensionless groups needed to describe a situation. After establishing this basic relationship between quantities with dimensions and dimensionless groups, the conservation equations for processes in fluid mechanics (Cauchy and Navier–Stokes equations, continuity equation, energy equation) are explained. By non-dimensionalizing these equations, certain dimensionless groups appear (e.g. Reynolds number, Froude number, Grashof number, Weber number, Prandtl number). The physical significance and importance of these groups are explained and the simplifications of the underlying equations for large or small dimensionless parameters are described. Finally, some examples for selected processes in nature and engineering are given to illustrate the method. 1 Introduction If we compare a small leaf with a large one, or a child with its parents, we have the feeling that a ‘similarity’ of some sort exists. -
Aerodynamics Material - Taylor & Francis
CopyrightAerodynamics material - Taylor & Francis ______________________________________________________________________ 257 Aerodynamics Symbol List Symbol Definition Units a speed of sound ⁄ a speed of sound at sea level ⁄ A area aspect ratio ‐‐‐‐‐‐‐‐ b wing span c chord length c Copyrightmean aerodynamic material chord- Taylor & Francis specific heat at constant pressure of air · root chord tip chord specific heat at constant volume of air · / quarter chord total drag coefficient ‐‐‐‐‐‐‐‐ , induced drag coefficient ‐‐‐‐‐‐‐‐ , parasite drag coefficient ‐‐‐‐‐‐‐‐ , wave drag coefficient ‐‐‐‐‐‐‐‐ local skin friction coefficient ‐‐‐‐‐‐‐‐ lift coefficient ‐‐‐‐‐‐‐‐ , compressible lift coefficient ‐‐‐‐‐‐‐‐ compressible moment ‐‐‐‐‐‐‐‐ , coefficient , pitching moment coefficient ‐‐‐‐‐‐‐‐ , rolling moment coefficient ‐‐‐‐‐‐‐‐ , yawing moment coefficient ‐‐‐‐‐‐‐‐ ______________________________________________________________________ 258 Aerodynamics Aerodynamics Symbol List (cont.) Symbol Definition Units pressure coefficient ‐‐‐‐‐‐‐‐ compressible pressure ‐‐‐‐‐‐‐‐ , coefficient , critical pressure coefficient ‐‐‐‐‐‐‐‐ , supersonic pressure coefficient ‐‐‐‐‐‐‐‐ D total drag induced drag Copyright material - Taylor & Francis parasite drag e span efficiency factor ‐‐‐‐‐‐‐‐ L lift pitching moment · rolling moment · yawing moment · M mach number ‐‐‐‐‐‐‐‐ critical mach number ‐‐‐‐‐‐‐‐ free stream mach number ‐‐‐‐‐‐‐‐ P static pressure ⁄ total pressure ⁄ free stream pressure ⁄ q dynamic pressure ⁄ R -
A Semi-Hydrostatic Theory of Gravity-Dominated Compressible Flow
Generated using version 3.2 of the official AMS LATEX template 1 A semi-hydrostatic theory of gravity-dominated compressible flow 2 Thomas Dubos ∗ IPSL-Laboratoire de Météorologie Dynamique, Ecole Polytechnique, Palaiseau, France Fabrice voitus CNRM-Groupe d’étude de l’Atmosphere Metéorologique, Météo-France, Toulouse, France ∗Corresponding author address: Thomas Dubos, LMD, École Polytechnique, 91128 Palaiseau, France. E-mail: [email protected] 1 3 Abstract 4 From Hamilton’s least action principle, compressible equations of motion with density diag- 5 nosed from potential temperature through hydrostatic balance are derived. Slaving density 6 to potential temperature suppresses the degrees of freedom supporting the propagation of 7 acoustic waves and results in a sound-proof system. The linear normal modes and dispersion 8 relationship for an isothermal state of rest on f- and β- planes are accurate from hydrostatic 9 to non-hydrostatic scales, except for deep internal gravity waves. Especially the Lamb wave 10 and long Rossby waves are not distorted, unlike with anelastic or pseudo-incompressible 11 systems. 12 Compared to similar equations derived by Arakawa and Konor (2009), the semi-hydrostatic 13 system derived here possesses an additional term in the horizontal momentum budget. This 14 term is an apparent force resulting from the vertical coordinate not being the actual height 15 of an air parcel, but its hydrostatic height, i.e. the hypothetical height it would have after 16 the atmospheric column it belongs to has reached hydrostatic balance through adiabatic 17 vertical displacements of air parcels. The Lagrange multiplier λ introduced in Hamilton’s 18 principle to slave density to potential temperature is identified as the non-hydrostatic ver- 19 tical displacement, i.e. -
Chapter 5 Dimensional Analysis and Similarity
Chapter 5 Dimensional Analysis and Similarity Motivation. In this chapter we discuss the planning, presentation, and interpretation of experimental data. We shall try to convince you that such data are best presented in dimensionless form. Experiments which might result in tables of output, or even mul- tiple volumes of tables, might be reduced to a single set of curves—or even a single curve—when suitably nondimensionalized. The technique for doing this is dimensional analysis. Chapter 3 presented gross control-volume balances of mass, momentum, and en- ergy which led to estimates of global parameters: mass flow, force, torque, total heat transfer. Chapter 4 presented infinitesimal balances which led to the basic partial dif- ferential equations of fluid flow and some particular solutions. These two chapters cov- ered analytical techniques, which are limited to fairly simple geometries and well- defined boundary conditions. Probably one-third of fluid-flow problems can be attacked in this analytical or theoretical manner. The other two-thirds of all fluid problems are too complex, both geometrically and physically, to be solved analytically. They must be tested by experiment. Their behav- ior is reported as experimental data. Such data are much more useful if they are ex- pressed in compact, economic form. Graphs are especially useful, since tabulated data cannot be absorbed, nor can the trends and rates of change be observed, by most en- gineering eyes. These are the motivations for dimensional analysis. The technique is traditional in fluid mechanics and is useful in all engineering and physical sciences, with notable uses also seen in the biological and social sciences. -
Introduction to Compressible Computational Fluid Dynamics James S
Introduction to Compressible Computational Fluid Dynamics James S. Sochacki Department of Mathematics James Madison University [email protected] Abstract This document is intended as an introduction to computational fluid dynamics at the upper undergraduate level. It is assumed that the student has had courses through three dimensional calculus and some computer programming experience with numer- ical algorithms. A course in differential equations is recommended. This document is intended to be used by undergraduate instructors and students to gain an under- standing of computational fluid dynamics. The document can be used in a classroom or research environment at the undergraduate level. The idea of this work is to have the students use the modules to discover properties of the equations and then relate this to the physics of fluid dynamics. Many issues, such as rarefactions and shocks are left out of the discussion because the intent is to have the students discover these concepts and then study them with the instructor. The document is used in part of the undergraduate MATH 365 - Computation Fluid Dynamics course at James Madi- son University (JMU) and is part of the joint NSF Grant between JMU and North Carolina Central University (NCCU): A Collaborative Computational Sciences Pro- gram. This document introduces the full three-dimensional Navier Stokes equations. As- sumptions to these equations are made to derive equations that are accessible to un- dergraduates with the above prerequisites. These equations are approximated using finite difference methods. The development of the equations and finite difference methods are contained in this document. Software modules and their corresponding documentation in Fortran 90, Maple and Matlab can be downloaded from the web- site: http://www.math.jmu.edu/~jim/compressible.html. -
Aerodyn Theory Manual
January 2005 • NREL/TP-500-36881 AeroDyn Theory Manual P.J. Moriarty National Renewable Energy Laboratory Golden, Colorado A.C. Hansen Windward Engineering Salt Lake City, Utah National Renewable Energy Laboratory 1617 Cole Boulevard, Golden, Colorado 80401-3393 303-275-3000 • www.nrel.gov Operated for the U.S. Department of Energy Office of Energy Efficiency and Renewable Energy by Midwest Research Institute • Battelle Contract No. DE-AC36-99-GO10337 January 2005 • NREL/TP-500-36881 AeroDyn Theory Manual P.J. Moriarty National Renewable Energy Laboratory Golden, Colorado A.C. Hansen Windward Engineering Salt Lake City, Utah Prepared under Task No. WER4.3101 and WER5.3101 National Renewable Energy Laboratory 1617 Cole Boulevard, Golden, Colorado 80401-3393 303-275-3000 • www.nrel.gov Operated for the U.S. Department of Energy Office of Energy Efficiency and Renewable Energy by Midwest Research Institute • Battelle Contract No. DE-AC36-99-GO10337 NOTICE This report was prepared as an account of work sponsored by an agency of the United States government. Neither the United States government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States government or any agency thereof. -
Compressible Flow
94 c 2004 Faith A. Morrison, all rights reserved. Compressible Fluids Faith A. Morrison Associate Professor of Chemical Engineering Michigan Technological University November 4, 2004 Chemical engineering is mostly concerned with incompressible flows in pipes, reactors, mixers, and other process equipment. Gases may be modeled as incompressible fluids in both microscopic and macroscopic calculations as long as the pressure changes are less than about 20% of the mean pressure (Geankoplis, Denn). The friction-factor/Reynolds-number correlation for incompressible fluids is found to apply to compressible fluids in this regime of pressure variation (Perry and Chilton, Denn). Compressible flow is important in selected application, however, including high-speed flow of gasses in pipes, through nozzles, in tur- bines, and especially in relief valves. We include here a brief discussion of issues related to the flow of compressible fluids; for more information the reader is encouraged to consult the literature. A compressible fluid is one in which the fluid density changes when it is subjected to high pressure-gradients. For gasses, changes in density are accompanied by changes in temperature, and this complicates considerably the analysis of compressible flow. The key difference between compressible and incompressible flow is the way that forces are transmitted through the fluid. Consider the flow of water in a straw. When a thirsty child applies suction to one end of a straw submerged in water, the water moves - both the water close to her mouth moves and the water at the far end moves towards the lower- pressure area created in the mouth. Likewise, in a long, completely filled piping system, if a pump is turned on at one end, the water will immediately begin to flow out of the other end of the pipe. -
6.2 Understanding Flight
6.2 - Understanding Flight Grade 6 Activity Plan Reviews and Updates 6.2 Understanding Flight Objectives: 1. To understand Bernoulli’s Principle 2. To explain drag and how different shapes influence it 3. To describe how the results of similar and repeated investigations testing drag may vary and suggest possible explanations for variations. 4. To demonstrate methods for altering drag in flying devices. Keywords/concepts: Bernoulli’s Principle, pressure, lift, drag, angle of attack, average, resistance, aerodynamics Curriculum outcomes: 107-9, 204-7, 205-5, 206-6, 301-17, 301-18, 303-32, 303-33. Take-home product: Paper airplane, hoop glider Segment Details African Proverb and Cultural “The bird flies, but always returns to Earth.” Gambia Relevance (5min.) Have any of you ever been on an airplane? Have you ever wondered how such a heavy aircraft can fly? Introduce Bernoulli’s Principle and drag. Pre-test Show this video on Bernoulli’s Principle: (10 min.) https://www.youtube.com/watch?v=bv3m57u6ViE Note: To gain the speed so lift can be created the plane has to overcome the force of drag; they also have to overcome this force constantly in flight. Therefore, planes have been designed to reduce drag Demo 1 Use the students to demonstrate the basic properties of (10 min.) Bernoulli’s Principle. Activity 2 Students use paper airplanes to alter drag and hypothesize why (30 min.) different planes performed differently Activity 3 Students make a hoop glider to understand the effects of drag (20 min.) on different shaped objects. Post-test Word scramble. (5 min.) https://www.amazon.com/PowerUp-Smartphone-Controlled- Additional idea Paper-Airplane/dp/B00N8GWZ4M Suggested Interpretation of Proverb What comes up must come down Background Information Bernoulli’s Principle Daniel Bernoulli, an eighteenth-century Swiss scientist, discovered that as the velocity of a fluid increases, its pressure decreases. -
Aerodynamics and Fluid Mechanics
Aerodynamics and Fluid Mechanics Numerical modeling, simulation and experimental analysis of fluids and fluid flows n Jointly with Oerlikon AM GmbH and Linde, the Chair of Aerodynamics and Fluid Mechanics investigates novel manufacturing processes and materials for additive 3D printing. The cooperation is supported by the Bavarian State Ministry for Economic Affairs, Regional Development and Energy. In addition, two new H2020-MSCA-ITN actions are being sponsored by the European Union. The ‘UCOM’ project investigates ultrasound cavitation and shock-tissue interaction, which aims at closing the gap between medical science and compressible fluid mechanics for fluid-mechanical destruction of cancer tissue. With ‘EDEM’, novel technologies for optimizing combustion processes using alternative fuels for large-ship combustion engines are developed. In 2019, the NANOSHOCK research group published A highlight in the field of aircraft aerodynamics in 2019 various articles in the highly-ranked journals ‘Journal of was to contribute establishing a DFG research group Computational Physics’, ‘Physical Review Fluids’ and (FOR2895) on the topic ‘Research on unsteady phenom- ‘Computers and Fluids’. Updates on the NANOSHOCK ena and interactions at high speed stall’. Our subproject open-source code development and research results are will focus on ‘Neuro-fuzzy based ROM methods for load available for the scientific community: www.nanoshock.de calculations and analysis at high speed buffet’. or hwww.aer.mw.tum.de/abteilungen/nanoshock/news. Aircraft and Helicopter Aerodynamics Motivation and Objectives The long-term research agenda is dedi- cated to the continues improvement of flow simulation and analysis capa- bilities enhancing the efficiency of aircraft and helicopter configura- tions with respect to the Flightpath 2050 objectives. -
Vorticity and Vortex Dynamics
Vorticity and Vortex Dynamics J.-Z. Wu H.-Y. Ma M.-D. Zhou Vorticity and Vortex Dynamics With291 Figures 123 Professor Jie-Zhi Wu State Key Laboratory for Turbulence and Complex System, Peking University Beijing 100871, China University of Tennessee Space Institute Tullahoma, TN 37388, USA Professor Hui-Yang Ma Graduate University of The Chinese Academy of Sciences Beijing 100049, China Professor Ming-De Zhou TheUniversityofArizona,Tucson,AZ85721,USA State Key Laboratory for Turbulence and Complex System, Peking University Beijing, 100871, China Nanjing University of Aeronautics and Astronautics Nanjing, 210016, China LibraryofCongressControlNumber:2005938844 ISBN-10 3-540-29027-3 Springer Berlin Heidelberg New York ISBN-13 978-3-540-29027-8 Springer Berlin Heidelberg New York This work is subject to copyright. All rights are reserved, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broad- casting, reproduction on microfilm or in any other way, and storage in data banks. Duplication of this publication or parts thereof is permitted only under the provisions of the German Copyright Law of September 9, 1965, in its current version, and permission for use must always be obtained from Springer. Violations are liable to prosecution under the German Copyright Law. Springer is a part of Springer Science+Business Media. springer.com © Springer-Verlag Berlin Heidelberg 2006 Printed in Germany The use of general descriptive names, registered names, trademarks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant pro- tective laws and regulations and therefore free for general use. -
An Asymptotic-Preserving All-Speed Scheme for the Euler and Navier-Stokes Equations
An Asymptotic-Preserving all-speed scheme for the Euler and Navier-Stokes equations Floraine Cordier1;2;3, Pierre Degond2;3, Anela Kumbaro1 1 CEA-Saclay DEN, DM2S, SFME, LETR F-91191 Gif-sur-Yvette, France. fl[email protected], [email protected] 2 Universit´ede Toulouse; UPS, INSA, UT1, UTM ; Institut de Math´ematiquesde Toulouse ; F-31062 Toulouse, France. 3 CNRS; Institut de Math´ematiquesde Toulouse UMR 5219 ; F-31062 Toulouse, France. [email protected] Abstract We present an Asymptotic-Preserving 'all-speed' scheme for the simulation of compressible flows valid at all Mach-numbers ranging from very small to order unity. The scheme is based on a semi-implicit discretization which treats the acoustic part implicitly and the convective and diffusive parts explicitly. This discretiza- tion, which is the key to the Asymptotic-Preserving property, provides a consistent approximation of both the hyperbolic compressible regime and the elliptic incom- pressible regime. The divergence-free condition on the velocity in the incompress- ible regime is respected, and an the pressure is computed via an elliptic equation resulting from a suitable combination of the momentum and energy equations. The implicit treatment of the acoustic part allows the time-step to be independent of the Mach number. The scheme is conservative and applies to steady or unsteady flows and to general equations of state. One and Two-dimensional numerical results provide a validation of the Asymptotic-Preserving 'all-speed' properties. Key words: Low Mach number limit, Asymptotic-Preserving, all-speed, compressible arXiv:1108.2876v1 [math-ph] 14 Aug 2011 flows, incompressible flows, Navier-Stokes equations, Euler equations.