It’s matlabassignment
I want you to do the assignment on page 274.Page from 232 to 239 are good reviews to help with the assessment.PowerPoint Presentation ENME 489F Fundamentals of Atmospheric Flight Dr. Dave Findlay
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[email protected] Course Goals… • Basic knowledge & capability required to address the solution of aerodynamic analysis associated with aircraft flight – considering low to high (supersonic) speeds • An understanding of first principles of flow physics involved in atmospheric flight in the range of 0<><3 (approximately)="" •="" mathematical="" formulation="" development="" as="" the="" classical="" theory="" of="" airfoil/wing/vehicle="" aerodynamics="" •="" exposure="" to="" past,="" present,="" ~future~="" state-of-the-art="" methods="" employed="" by="" applied="" aerodynamicist="" (including="" an="" appreciation="" for="" the="" inherent="" limitations="" of="" the="" techniques)="" course="" content="" main="" topics="" •="" how="" do="" things="" fly?="" •="" fundamentals="" of="" fluid="" dynamics="" •="" subsonic="" (incompressible="" aero)="" •="" compressibility="" •="" supersonic="" aero="" •="" transonic="" aero="" key="" items="" of="" interest="" •="" first="" of="" two="" semester="" series="" toward="" introduction="" to="" fundamentals="" of="" air="" vehicle="" aeromechanics="" •="" prerequisite:="" •="" fluid="" mechanics="" •="" differential="" equations="" •="" thermodynamics="" (strongly="" recommended)="" •="" matlab="" •="" numerical="" methods="" (recommended)="" •="" required="" textbook:="" fundamentals="" of="" aerodynamics,="" by="" j.d.="" anderson="" •="" recommended="" textbook:="" theory="" of="" wing="" sections:="" including="" a="" summary="" of="" airfoil="" data,="" by="" abbot&="" vondoenhoff="" expected="" student="" learning="" outcomes="" of="" course…="" •="" an="" ability="" to="" apply="" knowledge="" of="" mathematics,="" science,="" and="" engineering="" •="" an="" ability="" to="" communicate="" effectively="" •="" (k)="" an="" ability="" to="" use="" the="" techniques,="" skills,="" and="" modern="" engineering="" tools="" necessary="" for="" engineering="" practice="" grading:="" •="" mid-term="" 30%="" •="" project="" 30%="" •="" homework="" 10%="" •="" final="" 30%="" •="" special="" consideration="" for="" class="" participation="" …be="" sure="" to="" ask="" questions!="" •="" a="90-100" •="" b="80-89" •="" c="70-79" •="" d="60-69" other="" me="" dept="" reg’s…="" university="" course="" related="" policies="" •="" for="" further="" details="" on="" course="" related="" policies="" as="" specified="" by="" the="" university,="" go="" to="" http://www.ugst.umd.edu/courserelatedpolicies.htm="" l="" http://www.ugst.umd.edu/courserelatedpolicies.htm="" approximate="" schedule:="" •="" week="" 6="" -="" review="" for="" midterm="" •="" week="" 7="" –="" midterm="" •="" week="" 13="" –="" project="" (wing="" analysis="" code)="" due="" •="" last="" week="" –="" review="" for="" final="" •="" tbd="" –="" final="" why="" study="" fundamentals="" of="" aeromechanics?="" •="" navy="" sponsored="" students="" will="" obviously="" be="" working="" with="" aircraft.="" •="" it="" is="" a="" vital="" key="" special="" case="" of="" fluid="" dynamics.="" •="" it="" is="" very="" cool!="" •="" flight="" sciences="" impact="" all="" of="" our="" lives…="" question:="" what="" are="" the="" top="" 5="" news="" stories="" since="" 1900?="" top="" news="" stories…="" 20th="" century:="" 1.="" 1945="" -="" u.s.="" drops="" atomic="" bombs="" on="" hiroshima,="" nagasaki:="" japan="" surrenders="" to="" end="" world="" war="" ii="" 2.="" 1969="" -="" american="" astronaut="" neil="" armstrong="" becomes="" the="" first="" human="" to="" walk="" on="" the="" moon="" 3.="" 1941="" -="" japan="" bombs="" pearl="" harbor:="" u.s.="" enters="" world="" war="" ii="" 4.="" 1903="" -="" wilbur="" and="" orville="" wright="" fly="" the="" first="" powered="" airplane="" 21st="" century:="" 1.="" 2001="" -="" bombing="" of="" world="" trade="" center,="" …9/11="" what="" is="" the="" common="" denominator?="" course="" content="" main="" topics="" •="" how="" do="" things="" fly?="" •="" fundamentals="" of="" fluid="" dynamics="" •="" subsonic="" (incompressible="" aero)="" •="" compressibility="" •="" supersonic="" aero="" •="" transonic="" aero="" the="" primary="" forces="" acting="" on="" an="" aircraft="" are…="" …the="" question="" is:="" how="" are="" they="" created?="" note:="" for="" straight="" &="" level="" flight="" the="" l="W" &="" t="D." note:="" aero="" deals="" with="" l="" &="" d.="" structures="" deals="" with="" w.="" prop/power="" deals="" with="" t="" &="" w.="" what="" are="" some="" ways="" one="" can="" produce="" lift?="" flapping…="" rotating…="" creating="" your="" own="" relative="" wind…or…="" can="" you="" produce="" your="" own="" lift?="" vectored="" thrust…="" however,="" lift="" is="" usually="" produced="" by="" a="" wing="" moving="" forward="" at="" an="" incidence…and="" the="" wing="" is="" built="" from="" a="" distribution="" of="" airfoils…="" note:="" the="" key="" is="" the="" “correct”="" shape="" of="" the="" airfoil.="" a="" (deg.)="" set="" the="" airfoil="" (and="" eventually="" wing)="" at="" an="" angle="" of="" attack="" (aoa)…="" the="" shape="" and="" aoa="" result="" in="" a="" pressure="" difference="" across="" the="" airfoil…="" the="" integrated="" delta="" pressure="" results="" in="" lift="" force…="" however,="" air="" resistance="" will="" also="" cause="" an="" integrated="" drag="" force.="" ultimately,="" the="" full="" configuration="" is="" important="" &="" complex…requiring="" detailed="" analysis/testing="" to="" ensure="" safe="" &="" effective="" flight!="" however,="" it="" depends="" on="" the="" medium="" in="" which="" you="" are="" flying…="" •="" vacuum="" (outerspace="" -="" e.g.="" rockets="" astrodynamics)="" •="" gas="" (atmosphere="" –="" e.g.="" air="" aerodynamics)="" •="" liquid="" (the="" seas="" -="" e.g.="" submarines="" hydrodynamics)="" •="" what="" makes="" gas="" &="" liquid="" mediums="" similar?="" •="" and…some="" vehicles="" fly="" in="" all="" three…="" today’s="" fundaments="" of="" atmospheric="" flight="" are="" built="" on="" the="" shoulders="" of="" a="" few="" scientific="" giants…="" atmospheric="" flight="" must="" abide="" by="" a="" few="" basic="" physical="" laws…what="" are="" they?="" •="" ~350="" year="" ago="" sir="" isaac="" newton="" made="" some="" clear="" observations="" of="" these="" laws.="" aircraft="" in="" flight="" are="" governed="" by="" them.="" •="" these="" laws="" are="" basics="" of="" classical="" physics.="" •="" air="" is="" a="" fluid="" system="" that="" abides="" by="" the="" natural="" laws="" of="" thermodynamics.="" •="" the="" laws="" of="" thermodynamics="" define="" fundamental="" physical="" quantities="" (temperature,="" energy,="" and="" entropy)="" that="" characterize="" thermodynamic="" systems.="" •="" the="" laws="" describe="" how="" these="" quantities="" behave="" under="" various="" circumstances.="" homework="" assignment="" number="" 1:="" •="" list="" and="" discuss/explain="" newton’s="" laws="" of="" classical="" physics.="" •="" list="" and="" discuss/explain="" the="" four="" basic="" laws="" of="" thermodynamics.="" sources="" of="" aerodynamic="" forces="" &="" moments:="" •="" all="" aero="" forces="" are="" due="" to="" only="" two="" basic="" sources="" (1)="" pressure="" distributions="" (2)="" shear="" stress="" distributions="" no="" slip="" sources="" of="" aerodynamic="" forces="" &="" moments:="" •="" all="" aero="" forces="" are="" due="" to="" the="" integrated="" effects="" of="" these="" two="" basic="" sources="" (1)="" n="Normal" force="" (2)="" a="Axial" force="" (3)="" l="Lift" force="" (4)="" d="Drag" force="" (5)="" r="single" resultant="" force="" (6)="" a="angle" of="" attack="" (7)="" vinf="freestream" speed="" inc.="" l="" &="" d="" typical="" forces…="" •="" define:="" force="" coefficient="" -=""> [ “Aero Force” / (qS) ] where, q = ½rVinf 2 = dynamic pressure S = reference area (usually wing planform area) = Chord X unit span (2D Airfoil) then, Vehicle Lift Coefficient = CL = L/(qS) Sectional (Airfoil) Lift Coefficient = Cl = l/(qc) similarly, Vehicle Drag Coefficient = CD = D/(qS) Sectional (Airfoil) Drag Coefficient = Cd = d/(qc) Typical Forces… where we also note that, CL = CNcos(a) – CAsin(a) CD = CNsin(a) + CAcos(a) We can further define, Moment Coefficient (in the pitch plane) = CM = M/(qSc) where, c=reference length M Flow over a wing… • Recall: Lift is a result of differential pressure… Pressure Coefficient…Cp • A common parameter for airfoil aerodynamics • Used to represent how the pressure is distributed across the airfoil (wing) surface where, p = local static pressure pinf = fresstream static press. −= − = q pp V pp C p 2 2 1 r Always plot w/ Neg. Up!!!!!!! End of Week 1 - Review Notes: Course Content / Main Topics • How Do Things Fly? • Fundamentals of Fluid Dynamics • Subsonic (Incompressible Aero) • Compressibility • Supersonic Aero • Transonic Aero Some basic definitions … assuming some background in fluids • Fluid: A substance that deforms continuously under action of shear forces. A fluid is composed of a large number of molecules, each with a certain position, velocity & energy which vary as a result of collisions with other molecules. In aerodynamics, we are concerned with describing fluid motion in spaces which are very large compared to molecular dimensions (thus, containing a large # of molecules.) The fluid in aerodynamics is generally considered a continuous material determined from statistical averaging in a unit volume. The assumption is that the smallest volume of interest is much larger than the molecular sizes. This is known as “Continuum theory.” Physics of Air… • Discrete molecules…transferring momentum/energy…”flowing” to regions of lower pressure… Higher density Lower density Some basic definitions … assuming some background in fluids • Fluid: Properties used to represent a fluid continuum are: T = Temperature P = Pressure r = density m = viscosity a = speed of sound These properties are observed on the macroscopic level. Definitions (continued) …in general, all are a function of position & time… Temperature (T) • Qualitative (ie, …it feels hot/cold…) – thus, an arbitrary scale is employed Pressure (P) • Force per unit area (due to rate of change of molecules rebounding from the surface) - thus, it is dependent on the local properties of the medium Density (r) • Mass per unit volume (in general, a function of composition, T & P) • Example: Equation of State: r = P/(RT) ; R = gas constant Definitions (continued) …in general, all are a function of position & time… Viscosity (m) • Constant (for given condition/time) of proportionality between shear stress & gradient of velocity • Shear Stress = m X (du/dy) • Note: this assumes “Newtonian Fluid” (ie, shear stress ~ rate of shear deformation) • Example: For air at T< 3000o="" k,="" m="1.458X10-6" x="" (t1.5/(t+110.4))="" with="" t="" in="" (ok)="" &="" m="[kg/(s-m)]" definitions="" (continued)="" …in="" general,="" all="" are="" a="" function="" of="" position="" &="" time…="" speed="" of="" sound="" (a)="" •="" speed="" at="" which="" an="" infinitesimal="" disturbance="" propagates="" through="" the="" fluid="" at="" rest="" •="" for="" a="" perfect="" gas,="" =="" √γ??="" •="" note:="" g="ratio" of="" specific="" heats="" g="1.4" for="" air="" (usually,="" ie,="" perfect="" gas="">< 4-ish)="" very="" high="" heat="" values="" can="" effect="" this="" property.="" definitions="" (continued)="" …in="" general,="" all="" are="" a="" function="" of="" position="" &="" time…="" similarity="" parameters…="" what="" are="" similarity="" parameters="" why="" are="" they="" important?="" the="" main="" (non-dimensional)="" similarity="" parameters="" of="" interest:="" mach="" number="M" =="" v/a="" (indicates="" level="" of="" compressibility)="" reynolds="" number="Re" =="" (rvl)/m="(" inertial="" forces="" viscous="" forces="" )="" equations="" of="" fluid="" motion="" •="" classical="" physics="" dictates="" conservation="" of="" mass,="" momentum="" &="" energy="" •="" these="" laws="" are="" employed="" to="" mathematically="" describe="" fluid="" flow="" based="" on="" the="" assumption="" of="" continuum="" mechanics="" for="" the="" medium="" of="" concern="" (ie,="" air)="" •="" we="" now="" seek="" to="" develop="" the="" basic="" equations="" that="" will="" represent="" these="" laws…they="" are="" in="" turn="" referred="" to="" as="" the…=""> Continuity equation (conservation of fluid mass) > Momentum equation (conservation of fluid momentum) > Energy equation (conservation of fluid energy) Continuity Equation S = Control Surface V = Control Volume (Fixed in Space) Moving Fluid Field Physical Principle: Mass can neither be created or destroyed Continuity Equation • Say, r = r(x,y,z,t) V = u(x,y,z,t)i + v(x,y,z,t)j + w(x,y,z,t)k Then, with… [Net mass flow out of V through S] = [time rate of decrease of mass inside V] (LHS) = (RHS) Physical Principle: Mass can neither be created or destroyed Eqn (1) Velocity Field Continuity Equation (continued) →→ →→ →→ •= =• =• S dSV dSV dSV r r (LHS) / S across V ofout mass ofelement V ofout both when positive Eqn (2) dS V dV V- (RHS) / V inside mass of increase V Vin mass totalV Vin element mass V V V V d t d t d dd = = = = r r r r Eqn (3) The instantaneous tangential vector field quantity V(x,y,z,t) = Velocity Vector Field Continuity Equation (continued) 0V ...reordering & (1) into (3) & (2) Substuting V =•+ →→ S dSVd t rr Eqn (4) dS V dV Integral form of the continuity equation Continuity Equation (continued) 0)( have...must wearbitrary, is V since thus, 0 V})({ gives... (4) into (6) gsubtitutin V))(( have, then we(5) into substitute & )( let, V)( )ˆ z ˆ y ˆ x :(note .Theorem".. Divergence" recall V V V =•+ =•+ •• = •• + + = →→ V t dV t dVSdV VA dAdSA kji S S r r r r rr r Eqn (5) dS V dV Eqn (6) Eqn (7) Differential form of the continuity equation Continuity Equation (continued) 0)( then, 0 and, ),,( ie, Flow"...Steady " of case Special aConsider =• = = V t zyx f(t) r r rr r Eqn (8) dS V dV Differential form of steady flow continuity equation 0 then, constant Flow"... ibleIncompress" of case Special aConsider =• = V r Differential form of incomp. continuity equation Eqn (9) Homework Number 2: • Consider a low speed wind tunnel sketched below. • If the motor diameter is