Wing Sections Without Layouts
Allen, C.F.
1947-02-01 00:00:00
out any required section; as an example using section x—x, no. 1, let 1=80", the chord at any By C F. Allen N the preliminary stages of the design of a wing multiplier for the ordinatcs=(15/11·7) x 110= Then the ordinate at each percentage of chord= it is sometimes necessary to obtain sections be 141. A table of ordinates is then constructed, see fore the drawing office or lofting departments ordinate at Table I. Similarly at the tip, the multiplier for the have had time to make layouts. The following ordinates=(10/11·7) x 30 = 25·64, the table of The foregoing has been written with the pro article is written to show one method by which ordinates being shown in Table II. cesses being split into various stages to make the these sections can be arrived at. Incidentally it The sections at the C/L and tip being known, to procedure clear; in actual practice the Tables may be added that the author has found by ex obtain the ordinates of any section along the I, II and III would be incorporated into one table perience that a greater degree of accuracy is met span:—subtract from the ordinate dimension at in the first place. with by the use of this method and it provides the C/L the product of the difference between the TABLE I a useful check against the layouts. ordinates at the C/L and tip divided by the wing ORDINATES FOR SECTION AT CENTRE LINE The procedure as described refers to a straight span multiplied by the distance out of the section CHORD -11 0 IN., T/C RATIO-15 PER CENT tapered wing shape, and is applicable to any simi from the C/L. lar structure provided it follows that form. % CHORD DISTANCE For example, section x—x, FIG 1; let 1 = 80", % CHORD UPPER LOWER UPPER LOWER FROM DISTANCE For the purpose of demonstration the plan taking ordinates at 0·10 of chord. L EDGE form of a wing (FIG. 1) is given in which it is re a 0. ·40 Upper ordinate at C/L =13·52" 4.9 3 4.93° 44·00 16·00 0 FROM ·0125 quired to find any section as at x—x. The basic 14 80 Upper ordinate at tip = 2·46" 1 375 7·61 2 68 ·50 55·00 0 L EDGE aerofoil section is Clark Y.H. (FIG. 2) the thick Difference . . . . =11·06". ·025 2·75 9·16 2·11 ·60 66·00 12·82 0 ness/chord (TIC) ratio at the C/L being 15 per Then the upper ordinate=13·52—(11·06/200x ·05 5·50 11·14 1·27 ·70 77·00 10 41I ·1414 cent and at the tip 10 per cent. Also Co=110", 80)=9·1". ·75 8·25 12·41 ·85 88·00 7 9 0 ·90 ·56 0=30 * and 5=200*. From this information the From the foregoing, Table III is constructed 13·52 ·10 11·00 ·56 ·90 99·00 5 35 1 41 sections at the C/L and tip are then worked out. giving the difference for all percentages of chord, 15·10 ·15 16·50 ·14 10450 4 09 ·95 1 9 7 Section at C/L. Chord=110", T/C ratio=15 per the final columns headed ∆/S being the difference 16·10 0 ·20 22·00 \ 00 110·00 2 22 2·54 cent. It is seen that the T/C ratio of the basic sec -r-span at each percentage of chord. ·30 33·00 16·50 0. tion (no. 2) is 11·7 per cent, so that the Using Table III, it is a simple matter to work TABLE II ORDINATES FOR SECTION AT TIP CHORD=30 IN., T/C RATIO-10 PER CENT DISTANCE FROM % CHORD % CHORD LOWER UPPER UPPER LOWER L. EDGE DISTANCE FROM 0 ·90 ·90 2·92 0 0 ·40 L. EDGE 12·00 ·48 ·125 ·375 1·39 15·00 2·70 ·50 0 ·025 1·67 38 ·75 ·60 18 00 2 34 0 ·05 1 50 2·03 ·23 ·70 1 90 ·02 21·00 ·075 2·46 ·15 ·10 2 25 ·80 24·00 14 4 3 00 ·10 2·46 ·10 27·00 ·97 ·26 ·90 4·50 2·74 ·02 ·74 ·36 ·15 ·95 28·50 ·20 6 0 0 2·92 0. 1·00 30·00 ·51 ·46 ·30 9 0 0 3·O0 0. TABLE III ORDINATES ORDINATES. DIFFERENCE A T AT TIP AT TIP. ftT DIFFERENCE % CHORD. UPPER UPPER . LOWER LOWER. UPPER . LOWER. ·0201 ·0201 4·0 3 ·90 0. 4·9 3 ·90 4·9 3 4 03 ·0311 7·61 6·2 2 ·0110 ·0125 1·39 2 68 ·48 2·2 0 ·0374 ·025 9·1 6 7·4 9 ·38 1·73 ·0086 1·6 7 2·11 9·11 1·0 4 ·05 11·1 4 2 0 3 1·27 ·23 ·0374 ·0052 ·075 10·15 ·70 ·003 5 12·4 1 2·26 ·85 ·15 ·0507 11·06 ·0023 2·4 6 ·56 ·10 ·46 ·0553 ·10 13·52 15·10 12·36 ·12 ·000 6 ·15 2·7 4 ·14 ·02. ·0618 ·20 16·10 13·1 8 0. 0. 0. ·0659 0 . 2·9 2 16·50 3·00 13·50 0. 0. 0. ·0675 0. ·30 ·40 16·10 13·1 8 0. 0. 0. 2·9 2 ·0659 0. 2·70 12· 10 0. 0. ·0605 0. ·50 14·80 0. 10·48 0. 0. 0. 0. ·60 12·82 ·0524 2·34 1·90 10·41 8·51 ·02 ·12 ·0425 ·70 ·14 ·0006 ·0023 ·80 7·90 6·4 6 ·56 ·10 ·46 ·0323 1·4 4 1·4 1 ·26 ·0219 ·90 5·35 ·97 4·3 8 1·15 ·0057 4·09 ·95 ·74 3·35 ·36 1·6 1 ·0167 ·0085 1·97 ·51 2·31 ·46 2·08 ·0115 ·0104 1·00 2·82 2 5 4 deflexion of the specimen while the stylus is Measurement of Strains Conclusions moved axially along the drum by a desynn coup No strain gauges of any sort had been fitted to Since the M.A.P. party was due to leave the ling to the load indicating carriage in the control the test specimen at the time of the visit. From Friedrichshafen area before the date of the air unit. The autographic measurement of deflexions conversations with the French officers in charge frame test, the French authorities were requested seems to have been still in the scheme stage since and with the Dornier staff it seems that Dorniers to send a copy of the test report, when available, it was not in use on the test. No further informa relied on mechanical gauges of the Huggenburger to the Royal Aircraft Establishment, Farnbor- tion was obtained on this point type and that they had no electrical strain gauges. ough. February 1947 51
http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.pngAircraft Engineering and Aerospace TechnologyEmerald Publishinghttp://www.deepdyve.com/lp/emerald-publishing/wing-sections-without-layouts-2g0VbW07Jh
out any required section; as an example using section x—x, no. 1, let 1=80", the chord at any By C F. Allen N the preliminary stages of the design of a wing multiplier for the ordinatcs=(15/11·7) x 110= Then the ordinate at each percentage of chord= it is sometimes necessary to obtain sections be 141. A table of ordinates is then constructed, see fore the drawing office or lofting departments ordinate at Table I. Similarly at the tip, the multiplier for the have had time to make layouts. The following ordinates=(10/11·7) x 30 = 25·64, the table of The foregoing has been written with the pro article is written to show one method by which ordinates being shown in Table II. cesses being split into various stages to make the these sections can be arrived at. Incidentally it The sections at the C/L and tip being known, to procedure clear; in actual practice the Tables may be added that the author has found by ex obtain the ordinates of any section along the I, II and III would be incorporated into one table perience that a greater degree of accuracy is met span:—subtract from the ordinate dimension at in the first place. with by the use of this method and it provides the C/L the product of the difference between the TABLE I a useful check against the layouts. ordinates at the C/L and tip divided by the wing ORDINATES FOR SECTION AT CENTRE LINE The procedure as described refers to a straight span multiplied by the distance out of the section CHORD -11 0 IN., T/C RATIO-15 PER CENT tapered wing shape, and is applicable to any simi from the C/L. lar structure provided it follows that form. % CHORD DISTANCE For example, section x—x, FIG 1; let 1 = 80", % CHORD UPPER LOWER UPPER LOWER FROM DISTANCE For the purpose of demonstration the plan taking ordinates at 0·10 of chord. L EDGE form of a wing (FIG. 1) is given in which it is re a 0. ·40 Upper ordinate at C/L =13·52" 4.9 3 4.93° 44·00 16·00 0 FROM ·0125 quired to find any section as at x—x. The basic 14 80 Upper ordinate at tip = 2·46" 1 375 7·61 2 68 ·50 55·00 0 L EDGE aerofoil section is Clark Y.H. (FIG. 2) the thick Difference . . . . =11·06". ·025 2·75 9·16 2·11 ·60 66·00 12·82 0 ness/chord (TIC) ratio at the C/L being 15 per Then the upper ordinate=13·52—(11·06/200x ·05 5·50 11·14 1·27 ·70 77·00 10 41I ·1414 cent and at the tip 10 per cent. Also Co=110", 80)=9·1". ·75 8·25 12·41 ·85 88·00 7 9 0 ·90 ·56 0=30 * and 5=200*. From this information the From the foregoing, Table III is constructed 13·52 ·10 11·00 ·56 ·90 99·00 5 35 1 41 sections at the C/L and tip are then worked out. giving the difference for all percentages of chord, 15·10 ·15 16·50 ·14 10450 4 09 ·95 1 9 7 Section at C/L. Chord=110", T/C ratio=15 per the final columns headed ∆/S being the difference 16·10 0 ·20 22·00 \ 00 110·00 2 22 2·54 cent. It is seen that the T/C ratio of the basic sec -r-span at each percentage of chord. ·30 33·00 16·50 0. tion (no. 2) is 11·7 per cent, so that the Using Table III, it is a simple matter to work TABLE II ORDINATES FOR SECTION AT TIP CHORD=30 IN., T/C RATIO-10 PER CENT DISTANCE FROM % CHORD % CHORD LOWER UPPER UPPER LOWER L. EDGE DISTANCE FROM 0 ·90 ·90 2·92 0 0 ·40 L. EDGE 12·00 ·48 ·125 ·375 1·39 15·00 2·70 ·50 0 ·025 1·67 38 ·75 ·60 18 00 2 34 0 ·05 1 50 2·03 ·23 ·70 1 90 ·02 21·00 ·075 2·46 ·15 ·10 2 25 ·80 24·00 14 4 3 00 ·10 2·46 ·10 27·00 ·97 ·26 ·90 4·50 2·74 ·02 ·74 ·36 ·15 ·95 28·50 ·20 6 0 0 2·92 0. 1·00 30·00 ·51 ·46 ·30 9 0 0 3·O0 0. TABLE III ORDINATES ORDINATES. DIFFERENCE A T AT TIP AT TIP. ftT DIFFERENCE % CHORD. UPPER UPPER . LOWER LOWER. UPPER . LOWER. ·0201 ·0201 4·0 3 ·90 0. 4·9 3 ·90 4·9 3 4 03 ·0311 7·61 6·2 2 ·0110 ·0125 1·39 2 68 ·48 2·2 0 ·0374 ·025 9·1 6 7·4 9 ·38 1·73 ·0086 1·6 7 2·11 9·11 1·0 4 ·05 11·1 4 2 0 3 1·27 ·23 ·0374 ·0052 ·075 10·15 ·70 ·003 5 12·4 1 2·26 ·85 ·15 ·0507 11·06 ·0023 2·4 6 ·56 ·10 ·46 ·0553 ·10 13·52 15·10 12·36 ·12 ·000 6 ·15 2·7 4 ·14 ·02. ·0618 ·20 16·10 13·1 8 0. 0. 0. ·0659 0 . 2·9 2 16·50 3·00 13·50 0. 0. 0. ·0675 0. ·30 ·40 16·10 13·1 8 0. 0. 0. 2·9 2 ·0659 0. 2·70 12· 10 0. 0. ·0605 0. ·50 14·80 0. 10·48 0. 0. 0. 0. ·60 12·82 ·0524 2·34 1·90 10·41 8·51 ·02 ·12 ·0425 ·70 ·14 ·0006 ·0023 ·80 7·90 6·4 6 ·56 ·10 ·46 ·0323 1·4 4 1·4 1 ·26 ·0219 ·90 5·35 ·97 4·3 8 1·15 ·0057 4·09 ·95 ·74 3·35 ·36 1·6 1 ·0167 ·0085 1·97 ·51 2·31 ·46 2·08 ·0115 ·0104 1·00 2·82 2 5 4 deflexion of the specimen while the stylus is Measurement of Strains Conclusions moved axially along the drum by a desynn coup No strain gauges of any sort had been fitted to Since the M.A.P. party was due to leave the ling to the load indicating carriage in the control the test specimen at the time of the visit. From Friedrichshafen area before the date of the air unit. The autographic measurement of deflexions conversations with the French officers in charge frame test, the French authorities were requested seems to have been still in the scheme stage since and with the Dornier staff it seems that Dorniers to send a copy of the test report, when available, it was not in use on the test. No further informa relied on mechanical gauges of the Huggenburger to the Royal Aircraft Establishment, Farnbor- tion was obtained on this point type and that they had no electrical strain gauges. ough. February 1947 51
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Aircraft Engineering and Aerospace Technology
– Emerald Publishing
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