US2331304A - Wing lift and aileron illustrator - Google Patents

Description

Oct. 12, 1943. E. o. CARMODY WING LIFT AND A'ILERON ILLUSTRATOR Filed Dec. 26, 1942 2 Sheets-Sheet 1 IE. l. Z

INVENTOR TTOR Y Oct. 12, 1943. E; o. CARMODY 2,331,304

WING LIFT AND AILERON ILLUSTRATOR Filed Dec 26, 1942 2 Sheets-Sheet 2 hr INVENTOR E. drnunli Cl. C. armn ATT NEY Patented Oct. 12, 1943 UNlTED STATE (Granted under the act of .*March 3, "1883 ace":

amended April 30, 19.28;]370 757): Q r

U Thisinvention pertains to aeronautics, par

ticularly to apparatus used in connection with instructions; in aeronautics, dynamic theory and practice in the art of flying. More specifically the present invention is a novel type ofcomtrate the effects of aileron control and the causes ,transparent sides and top. The forward end of i the conduithas a'screenfS and funnel'inlet "6,

mountedthereon, glitthe rear end of theconduit'is a funnel shapedicowling I at the end of 5 which is mounted a fan 8 driven by. a motor, 9. bined wind tunnel and model aircraft to illusof istallingPQMany students find it difficultto;

grasp the fact that in orderto maintain a plane in a bank it is not necessary to keep the stick in the inclined position. Another thing that is sometimes difiicultfor the instructor to explain a v .or-thestudent' to grasp is the effect of. variation in the angle of attack of theairplane w n r itsfl nes d h i t a d a h t r r tics, and the reasons therefor. i I 1 .The, object. of this invention is simple, apparatus which will clearly illustrate the efiects-above referred to and will thus save ---time, efiort and expense not only-on the part of the instructor but also, on the part. of the -.;students, and'with -better. results in the proficiencytof' the class as a whole as well as a pos- Other objects of the present disclosure will appear from the following; description thereof I -.taken' ,in connection with the accompanying -drawingsain which 3.: 'Figwl isaperspective view of an form of the present device;

Fig. 2 is a perspective of the airfoil, and its :yconnections mounted in one of the compart- Lmentsof the device; I

' Fig. 3 is a perspective of the details of-g the' ;;control .means for the ailerons of the airplane ,i model. in theother compartment ofthe device,-

and 'Figs. 4 and 5 are details of the sliding connec- In the forward compartment; an airfoil I0 is mOuntedon a-shaft I'l having'arms l2 extending in line with the airfoil and pivoted at their ends.to 'pairs of vertical bars l3 which extend downward throughthe bottom. of the conduit ;into' the base, where "each 1 pair is pivotally' con'- nected- "two opposite arms of vertical cross gn emberllt- .-The other two arms of these cross,-

- membersf'are' connected byhorizontally extendto make a "illustrative mg bar's [5} which are. pivotally connected to said arms at one end-Land falso pivotally' connectedftoj'afpair of; armsll lat. the otherend, the arins 116 ,being mdunted' on a shaft l1 to which a controlknobflfl is'attached on the out side ofthe base- The knob has .a pointer 19 working across a dial 20 to indicatetherelative positionof 'theairfoil' with respect to the air stream intheconduit. These bars and cross armsconstitute 'a J v-floatin'g v device attached to -the} airfoil which is hung .by' means of strings 2|, attachedtothe ends of shaft ll and'passed over pulleys 22 anddown through the'floorof the-conduit intoZ'the base. of the device where they aretie'd to a counterweight bar .23 and also I by means ,or arms 24 tola shaft Zimdunted in theba'se and extending outside for. connection Qfi al binter 26 to indicate onfa amen the outside 10: the base the lift of) the airfoil, the'force of the, lift beingQcOunfiQ IbaIancedby a mechanism 4}! while the counterweight bar 23 ismerely to. balance the weight of the airfoil. In order to -show-the drag characteristics of the .airfoil under. ;any particularconditions the shaft. l l is also connected by strings "2'! passed over pulleys 28 and tied to the ends' of armslzaon the-shaft -30 which extends outside of the base to receive a pointer 32 indicating the drag on 'a'dial .33. A

tion between the manual control and the rotat- "T able aileron controls.

Figs. 6 and 7 illustrate the yarn or strings.

fluttering in. a manner to show two dififerentresults under conditions .of smooth flow and vibration respectively. L

- Similar numerals will be .used in designating {the-same parts in the several views of the draw- ."counterweight 3| mountedon the shaft is "used to 'counterbalancemthe drag of the airfoil, the di'albeing calibrated to show relative drag. either-of these indicators on the outside of v the base it is not important to show the exact drag or liftbu't merely the relative values thereof under different conditions of air speed and angle ofattack, A I .fj'.

. In the-. e rlcom m nt he con itf :xaircraft model 34; is mounted rotatably on a hori- :zontalhollow shaft '35 which runs fore and aft *throughthe longitudinal axis of :the model and --whichfl s rigidly mounted onstandards 43 at its bver thefsurface p v v an le of attack'has"been"increased to th'je-point and having arms 38, 38 extending in,joppositei' directions from the axis of said shafts and having links 39, 39 pivotally connected thereto atone end and pivoted at their other ends to pins; 51):;

mounted on opposite sides of a block 4|, The

outer ends of pins 48 are mounted tdsli'de in horizontal groove members fl mounted inethe frame of the model. The block fl; islljoid to fit loosely over the shaft 35 inside themodel and has a cut-out portion th'ereiri-ior the irisr tionof a collar "M !Which-isalso bored tdl'oosly fit ever this "shaft arid {to slide therealdhg response t'o th axial niovementsof the block.- pin 5 is passed thldllgli this OIlal' and tlif c ii'gh a slot "in the shaft am to it is connectedt'he 'h of the Techno wire 41 which "passes tfiit thrdugh'the rear end of the shaft and through fa flexible hoset'o the undersidedf the topof-th'e when t b 'iqv r e f- 'ihi nt 'di tier S for 'nioving the 'jcontrol wire axiallylso s to manipulate the ailerons through the dev'id just described in resptnse "to thecorrespondirig"movements of control"s'ti"ck36";" The model has aeh- 'ffietio'n hear ngs-by means or which: it is"rndiir'ited w o shaft 3 s at least one offw'hicli'is a" t hnistbaring' tokeil the mean from slidiii 'piiehgthsha tsa'f i Theis'creehs' and 5"aremade of parallel flutes j'tiire tedjm line witli tliecondiiit soas'to stra ght- ;enisu't the iidw of auto the conduit and elimif'ate any possifiie' eddy currents-whicir niight Yiitlierwise dccurfas theresult or outs'idefii'stur'b- "mc's as the air passes'into one eorhpart'rnehtand 'tnnintbtheothny" p t the parade er s ame the hearse of theair seem thr ugh the? rstj cemiiarthieht"to-"enema tlie sniiiehrto hatter v sualize the areas or arying, the httitiideof the airfoil on the semiaui g air st'reaihq Short strands'of the yarhfinay befittachedfldir'ectlyt the su face hr ihairicn "at-various suitable same; In operating th r'es- "elit device thi fant is started and 'iatlng the controls t an the 'efiectsmntioned above maybe' observed parent Waller): the'coi'iduit. k ing" flying" speed may be simulated by varying through'the trafns- The effector vary- "the speed of theran:

he air Hui-rents flowing shiiijitlil of breaking ppthis'smooth flow on th upper surface,"at*the" particular air speed, aha the broken currents are irregular and causethewing i it flutter or vibratei n? the "angle is not reduced "immediately; the lift drops suddenlyand the drag increases. The angle c6r iEspbndi-hgf" toi mailirnuin lift atafiypaineu arair speed wm be hated to be Just/bloW-this critical angle" here i the current begins'to break awayfroin-the u-p'rier surface; 1 This critical angle is i also found to be smaller with: increasing ah spe'e'ds; lFtirth'er-i' more, it will be found that for any air speed, the angle for maximum lift to drag ratio is slightly less than that for maximum lift.

i Two of the important features that should be thoroughly impressed 0n the new flier are the effect and manipulation of the aileron control and the reaction bet-Ween an airfoil and the airstream 'uiitl'e'r 'diiferefii'lf conditions" of angle of attack and an speed. Tlis'efea'tufs are visibly ,and clearly illustrated in the model air tunnel "or the present invention. This device gives the student the opportunity of actually manipulating the aileron controls and practicing placing the-mane to any desired degree, learning alwaysto return the stick to neutral position in order to maintain any particular degree ofb'ar'iking. It also serves to clearly illustrate, inr-a much shorter time and more impressively, l-th'; reacfiic rijbi'tyieeh an airfoil and the airstream, than could be learned by lectures and sketches on theblackbeiirdi The st'ix'dei it can actually observe the anstreaiaurr'eats their eiredtson any airfoil; as the wingof swan-1m the control ervarym the eagle I "of attackor' changing the speed oi tnairsti-eam, and watching the r'ela-tiveeffcts on lift; drag a-nd -thfe air cu-rre' s;- riotingarse th till ifii- 150mm characteristics of sta*ll ing"- aiidthe Vibrations: occurring just before the stem." ---Ha1vi'r'i g qfiade'these' ehsrvatiahs, he iha yrhife readily "recognize tfie syriibtoms of an -orie6rfiing stall actual flight; and earl mus -av rs possibly senous -eehsequehes by taking t'iiiiely cc uritrmeasures; -rrrese observatibrfi will 51556 irr'iiars himwith the necessity of fiiaIiitEiIilinE fiyliig spe atoavoiqsta isifiaetiiai fiins. it will betha't'al mime-inexpensive device-has bencns'tmeted which win "save nine "and effort as Well as 'xIiens'e ifi-tfiatit not only eliminates the" necessity for the" 6r stiident to-speiil an excessive amounts! tlfne'fr instructions which-would otherwise Be necessary -bi1t also saves-theme or exb'ensite fun' seine equipment and the iinnecessary hazards ordiiifimiar'ytiaihinc; i I I vaheus meaifieanens msizeand form-as W611 as arrangement may be made in this device i without awaiting from th' sco e ofthe invention 'wllic'h isdefined hy the-appended claims This invehtio'n'inaii be madeor' used by'tif ier the Government of the United States for "g'bvefhiiiiit'al purposes Without the payment to'ifie of, any royalties thereoii dr therefor, ii i 'whatIlalm 13:

21, 1.- wind' tunnel mountedien a=base:hamg transparent sides and top, anainilaiie' inodel fir'citatablymounted on its longitudinal aiiisthrerm Eifoicomplete unohstrulz'tedrotationg aileron control means for said plane extended to th wall of the tunnel for operation by a stick on them -side thereof fornhstriiction and practice irur- -po'ses. 1

2. A wind tunnel mounted im a 'ba's' ha'ving =transparentzsides and .toiij a samjiletaii-foil mounted'transversely 01118) horizontal shaftxhuiig -by' sti'in'gswiea toits' ends and passinghver pulleys at the top of the tunnel thhaewn' into I the base to eha's on a shait'which extends to 1m" th'bfits'id or the Base and h'a'a fitlifitf end, a counterweight for balancing the weig'fitbf i the airioiiconhe'ctedtb said strings m the Base, means for turning said pcinter shaft in to 'the 'lift on the'airfoiLand a'iscale un which '75- said ipointer indicates. the amoimt of lift.

transparent sides and top, a sample airfoil mounted transversely'ona, horizontal shaft hung by strings tied to its ends and passing overpulleys at the top of the tunnel then down into thebase,

to arms on a shaft which extends to the outside of the base and hasa pointer on its end, acounterweight for balancing the weight of the airfoil connected to said strings in the base, means for turning said pointer shaft in response to the lift on the airfoil, a scale on which said pointer indicates the amount of lift, floating means for controlling the angle of attack of the airfoil by a knob on the base, and indicator means on the base connected to the airfoil for showing the amount of drag.

4.'A wind tunnel having two compartments tandem with transparent walls, an airplane model mounted rotatably on it longitudinal axis in one compartment for complete unobstructed rotation, a typical wing floatingly mounted in the other compartment, a control stick on the outside of the wind tunnel for controlling the ailerons on the model airplane without restricting its rotary motion, a manual control for the angle of attack of said wing operated. from the outside of the wind tunnel, means for indicating relative lift and drag of said Wing, the compartments being separated'by a screen for straightening out the airflow through the tunnel, another such screen at the inlet end of said tunnel, a suction fan at the other end of said tunnel, and means for controlling the speed of operation of said fan.

5. A wind tunnel having transparent walls, an airfoil hung therein in flying position, floating control means for varying the angle of attack of said airfoil, means for indicating the relative lift tive drag on said airfoil.

6. A wind tunnel having transparent walls, an airfoil hung by strings loosely attached to the n on said airfoil and means for indicating the relaend of a transverse shaft through the airfoil and passed over pulleys at the top of the tunnel and down through the base of the tuimel'where they are fastened to a counterweight to-balance theweight of the airfoil, indicator means responsive to the lift ofthe airfoil, another indicator means responsive to the drag of the airfoil, and floating connections from the airfoil. to a manual control v for adjusting the angle of attack of said airfoil.

3 7. A wind tunnel having transparent walls, an airfoil hung by strings loosely attached to the ends of a transverse shaftthroughthe airfoil and passed over pulleys at the top of the tunnel and down through the base of the tunnel where they are fastened to a counterweight to balance the weight of the airfoil, indicator means responsive to the lift of the airfoil, another indicator means I responsive to the drag of the airfoil, floating connections from the airfoil to a manual control for'adjusting the angle of attack of said airfoil, and means for varying the air speed through the tunnel. g EDMUND O. CARMODY.

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