THE UNIVERSITY OF MICHIGAN COLLEGE OF ENGINEERING Department of Naval Architecture and Marine Engineering RESISTANCE AND PROPULSION TEST RESULTS ON TWO MODELS 1. Series 60, CB =.80 2. High Speed Cargo Ship PD 108-S5-0 Finn Co Michelsen R. B. Couch Hun.Chol Kim ORA Project 04652 under contract with: DEPARTMENT OF COMMERCE MARITIME ADMINISTRATION CONTRACT NO. MA-2564 WASHINGTON, D.C. administered through: OFFICE OF RESEARCH ADMINISTRATION ANN ARBOR March 1962

Io INTRODUCTION This report presents the results of resistance and self-propulsion tests of two models carried out at the Ship Model Towing Tank of The University of Michigan from October to December, 1961, as an extension to two model tests previously performed under the sponsorship of the Maritime Administrationol These earlier tests showed that good results could be obtained with a 1i-foot (LBP) model size as compared to the 20-foot size normally used at David Taylor Model Basin. It was decided, however, to investigate further the correlation of results obtained with these two model sizes, specifically for a fuller model, such as Series 60, CB =.80, In addition, a finer model, the Maritime Administration design PD 108-S5-0, was tested so that correlation data for a complete range of block coefficients would be available. This model was tested at two draft conditions~ H1: Loaded Displacement H2: Light Displacement The model numbers are as follows: Series 60, CB =.80: U of M 932 (DTMB 4214) PD 108-S5-O: U of M 933 1

II. SUMMARY Results of the resistance tests are summarized in Figs. 1-4, and of the open-water and self-propulsion tests in Figs. 5-9. The 1947 ATTC friction formula is used throughout. Figures 2 and 4 show the Cr versus speed-length ratio for models 932 and 933, respectively, after blockage effects have been corrected for. Blockage corrections are based on Dr. Hughes' recently published paper.2 Instead of a constant K value of 1.7, as recommended by Dr. Hughes, a variable K value depending upon speed-length ratio and block coefficient was used, however. The functional relationship between K and these variables was derived from the differences between test results as obtained at DTMB and at The University of Michigan. A plot of K for various block coefficients is shown in Fig. 10 Turbulence stimulation was the same as for previous models,1 with an additional trip wire placed at the aft shoulder in model 932. At low speeds this wire seemed to decrease the resistance slightly. Model data are shown in Tables 1 and 2, the line drawing of model 933 in Fig. 11, propeller data in Table 3, and propeller drawings as Figs, 12 and 13. 3

III. MODELS, EQUIPMENT, AND TEST PROCEDURES Ao MODELS It is believed that a model size of 14 foot (LBP) has now been tentatively established as a standard size at The University of Michigan, For conventional ship forms this choice normally results in a propeller size sufficiently large so that propeller scale effects are negligible. Blockage effects of models of this size are not too large and can furthermore be properly accounted for. Both models tested were of 14 foot length and made from wax of the same composition as the wax used at DTMBo B, EQUIPMENT The only major change in equipment used for this test series is the new towing carriage installed during the summer of 1961. This new carriage permits a much better speed selection for the self-propulsion tests. The speed variations are still larger than desirable, however, and it is therefore the practice to take instantaneous simultaneous readings at moments when the carriage speed is fairly constant, Co TEST PROCEDURES Test procedures with the new carriage are the same as before. Details of these are given in Ref. (1). Open-water propeller tests were run with the 1-horsepower dynamometer, whereas for the self-propulsion tests the smaller 1/8-horsepower dynamometer was found to have sufficient capacity. Propeller number 5 was checked for open-water characteristics with the 1/8-horsepower dynamometer over a limited range of advance coefficients, 5

IV. DISCUSSION OF RESULTS A. MODEL 932 For this model full-scale predictions for a 600-ft ship have been plotted together with the DTMB data, Where only one line appears in the figures complete agreement between the two data exists. The main reason for the differences in rpm can be attributed to a discrepency in pitch ratio of propeller number 4, In other respects the agreement between our results and DTMB results is goodo It should be pointed out here that blockage corrections were made on the'basis of a speed increment rather than a resistance increment as done previously. This resulted in a very good correlation in Cr which could not be obtained if a resistance increase was used. It is therefore felt that the method employed now is sound, Both approaches will lead to essentially the same EHP. The blockage correction is described in more detail below, Bo MODEL 933 It is believed that the EHP tests of this model at the two drafts are good. The self-propulsion tests gave a considerable amount of trouble, however, and unless an unusual flow condition exists at the propeller disk it is difficult to believe the data obtained. To eliminate any possibilities of errors in the interpretation of test results, the model was tested at three different times, The propeller was also tested several times, twice with the large dynamometer and once with the small one, As far as the propeller is concerned, a good agreement exists between individual tests, and in regard to self-propulsion tests relatively good agreement was reached, although the scatter of test points was a little more than usual, On the basis of overall results, it is obvious that this model will require a great deal of more detailed investigation; in particular, a study of flow conditions in the neighborhood of the propeller should be undertaken, Such a study will be made as soon as additional instrumentation becomes availableo Under the circumstances results presented on this vessel must therefore not be considered as final, 7

V. BLOCKAGE EFFECT Recently Dro Hughes has published a paper on blockage effects in which he proposes a slightly changed version of the method for accounting for these effects. 2 From a theoretical consideration he proposes that the increase in velocity due to potential flow around the ship should be given by 5V _ m V -mF (1) where V m = h = - Vgh with 7 = volume displacement of model L = length of model A = cross sectional area of tank V = model velocity h = depth of tank, To make Eq. (1) give velocity increments in agreement with experimental results, Dro Hughes proposed to multiply the right hand side of the equation by an empirical constant K = 1.7. His results indicated a great deal of scatter, and it was realized the K was probably a function of the speed-length ratio. It was therefore decided that on the basis of the Michigan and DTMB results obtained for the Series 60, CB =,60,.75, and.80, the required value of K for correlation of data should be plotted to determine if any empirical functional relationship between K, CB and V/IL could be foundo Fortunately the data seemed to reveal definite trends which are shown in Fig. 10. An empirical equation derived from the data mentioned above has been formulated so that the EHP calculations could be programmed for the digital electronic computer. 9

VI. REFERENCES 1o Resistance and propulsion tests on two Series 60 models, Finn C. Michelsen, R. B. Couch, and Hun Chol Kim, The University of Michigan ORA, Ann Arbor, Report No, 03509-1-F, April 1961, 2o "Tank Boundary Effects on Model Resistance," G. Hughes. Transactions of Royal Institution of Naval Architects (submitted for publication). 11

APPENDIX

5-_ cn -J 4 z V) X 0 CD /] In // 20 __'O/ /, -Speed-Length Ra io 0.3 0.4 0.5 0.6 Q7 O. I 2 3 4 5 MODEL SPEED, FT/SEC Fig. 1. Total resistance vs. model speed, Series 60,.80 block, U of M 932, 14-foot model with rudder (corrected for blockage effects). Water temperature 73~F. ^ ____ — - __ 1^

3.0 2.8 2.6 2.4 -22.0 1.8 1.6 ~~.4 ~~~~ SPEED-LENGTH RATIO, VK/V/Wm Fig. 2. CG vs. speed-length ratio, Series 60,.80 block. -4~ U of M 932; ---- DMB 4214. 16

13 --- 3- - - ---- - --- 12 _-_-_-____ -- - -I -IL 8 0 n7 w 7 w Loaded Displacement (H,) g 3Light Displa.cement H,1) model with rudder (corrected for blockage effects). Water temperature 740F.

Loaded Displacement (Hi), o 2~-~ _z~~ 0 2 _-_-Light Displacement(H2) ___-0 __...40.50.60.70.80.90 1.00 1.10 1.20 1.30 SPEED-LENGTH RATIO Fig. 4. Cr vs. speed-length ratio, PD 108-S5-0. 18

0.8 0.6 / ~ 0.5..... 0Ja 60, C0 =. 80). 0.2 ~ ~f- ~ ~ ~ ~^ ~^ ~ ~1~~19 0.1 0.1.2.3 4.5.6.1.8. O 1.0 1 1.2 J'V Fig. 5. Propeller open-water test results, U of M propeller No. 4 (Series 60, CB =.80). 19

0.8 0.7... 0.5 —_ o.s I,~ 0/.1. 0.3 0..2.3 A..5... 1.1 1 Fig. 6. Propeller open-water test results, U of M propeller No. 5 (PD 108-S5-0). 20

eh.120 0 o Iil ( 0 " 90 -: PC. 20 80 0 aQ70 e / _ _ ~_ _ _ _ _ -= _ _ -=1= =6.. a. 50 32 4_30~~ ~ ~ ~ ~ ~6^~ ^ ~0 / propeller _No. 50. _ -~~~ —rsuts -c, o..fo~21 T 32.40 1 28.30 i 16 24 z: ~~~~~~~~21 10 12 13 14 15 16 17 18~~~, SHIP SEED I KNOT Fig,7 hppousv hrceitc o 0-fo........CB.8j U f' propeller~~~~~-: No/_DNBrsls

.80- -- e e.70 ~ ~~-~======.-~ ~^~~ ~_ _ - 50.60 ~~~~~~~ 48 120 - 46 G -~ - ~ - ~ - - ~ ~~ -~ ~ ~44 o eh 0. 100 er 42 err o 40 0 _ 80-~ ~-~ 38 aRC. - o 60 ~ - -34 ~ ~,- ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~^ ~ ~ -^ ~ ~32 I 0 40 ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ - ~ ~ ~ ~ - ~ ~ / ~ ~ 30 aC,) 28 - — / o 26 o j,80 24 < JT:: d5 22 o.60 - 20.30 18 -:z3C15~ ~ ~~~~~~~~~~1 -.20 / 1 WT ~~~~~.15~W 5 12.I 5/t 14.10 ~ ~ ~ ~ ~ ~ ~ - - ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ 6 0 10 12 14 16 18 20 22 24 26 28 SHIP SPEED IN KNOTS Fig. 8. Ship propulsive characteristics, U of M propeller No. 5 (PD 108-S5-0), loaded displacement. 22

.80 - ep.70 - 1 1 1 1 1 -I - 50 a.60 11 1/ ~ 1 11 - 1- -48 120 - — ~~~ ~~~ ~~~ 1 46 ~ ~.c~ ~ ~ ~: ~ ~ ~ ~ ~ ~ ~ ^ ^ ~ ~ ~ ~~~~ 44 eh 10042 0 / 0 40 Fi. PC. Sla, I 38 a. // w.90 3024 0 470 1 1 I I I I I I / _ _,, 0 28 w n,) 26 o.90 -24 - 10 12 14 16 18 20 22 24 26 28 SHIP SPEED IN KNOTS Fig. 9. Ship propulsive characteristics, U of M propeller No. 5 (PD 108-S5-0), light displacement. 23

- -- ~ ~~~~~~~/^ 2~~L ~ ~^ ~ ~____-/~_____- ___ ___ I..".. ^ 7 ^~/ /,, / /.2.8 4.5.0.7.~.9 1-0II 1.2 v/rf/ Fig. 10. Blockage correction factor K.

QWL.~~ A 20 1i 19 la'*........tI' " ~ o ~'','t ui ~i'~ ~:'~ ~ ~^ ~' ~~ STERN PROFILE X BOW PROFILE IODY PLAN Fig. 11. The line drawing of model 933. 29

iN^Td W -PRWOJE-CT1O XP E= PA &0 PITCJ cL & E 5180. h - M.t^TCkkEL C ~~ ~ 253 6.^5/ - ~ ^~^-V ~i.052 8.92 -;.^~~t ro.65.: ~2"O G651 no~~~~~~~~~~o -~ ~ ~ ~~Fg 12.. Proplle dr-ig U o~f^\ Mv Prpelr o.4 ~'-E;F — ~ \80 7 0 -0. ^As. -~ — - -1 \\7..0/8 a-/.08 4,. ~. IL Fi ~~~7_~~~~0. 723 ~ ~ ~ ~ ~ ~~~~~ 468 090~~44 7 70:d~~SL SFg. 12. Prpeller drwing, U o M Propeler No. 4

_ R-.~~ w/,. w^^ /~^'90 34 - 02 - <062 \t-r 3./ 74 _'V ~ 7 " f 062 f'/ 10/2.67 ~-''..06 2. 7 0-11- 3.3 -062 - ~m OSiE JIG NO." \ a -— /~ 1 0 0 -'1 00.7602 " ^i.BORE'" dr Fig. -1, U07PopaUo Fig. 13. Propeller drawing, U of M Propeller No. 5.

TABLE 1 MODEL DATA Model No. 933-H1 (Loaded Displacement) Model No. 933-H2 (Light Displacement) Ship PD 108-S5-0 Ship PD 108-S5-O Ship Owner MARAD ORA No. 04652 Material: Wax Ship Owner MARAD ORA No. 04652 Material: Wax Model: X = 37.714 Ship Model: X = 37.714 Ship LOA 15.065 ft; 180.780 in. 568 ft-2 in. LOA 15.065 ft; 180.780 in. 568 ft - 2 in. LWL 14.292 ft; 171.504 in. 539 ft LWL 14.292 ft; 171.504 in. 539 ft LBP 14.000 ft; 168.000 in. 528 ft LBP 14.000 ft; 168.000 in. 528 ft B 2.148 ft; 25.772 in. 81 ft B 2.148 ft; 25.772 in. 81 ft H mean 0.715 ft; 8.578 in. 26 ft- 11-1/2 in. H mean 0.557 ft; 6.684 in. 21 ft fwd 0.477 ft; 5.724 in. 18 ft A = 774.4 lb at 8.578 in. Draft, 74~F 18,544 tons, S.W. aft 0.636 ft; 7.632 in. 24 ft W.S. bare 35.399 sq ft 50,350 sq ft A = 554.5 lb at 6.684 in. Draft, 74F 13,660 tons, S.W. rudder 0.316 sq ft 450 sq ft W.S. bare 29.543 sq ft 42,020 sq ft Total 35.715 sq ft 50,800 sq ft rudder 0.316 sq ft 450 sq ft Ax/Tank Area 0.782% Friction Basis: 1947 ATTC Total 29.859 sq ft 42,470 sq ft Designed Speed 6.325 ft/sec ACf... 0.4 x 10-3 Trial Speed 6.875 ft/sec V/L = 0.99; 23 KTS Friction Basis: 1947 ATTC D V/JL = 1.08; 25 KTS ACf... 0.4 x 10lMODEL TEST CONDITION Draft Mean: 8.578 in. Turbulence: Trip Wire MODEL CHARACTERISTICS LBP/LWL CpA 0.58 B/H 3.004 LCB, %LWL 0.004 of LE/LWL 0.465 CPV 0.755 S/ATL 15.9 LX/LWL 0.025 CPVF 0.85 A/(L)3 118 LR/LWL 0.510 CPVA 0.68 1/2 aE 6.50 CB(LWL) 0.553 CW 0.732 CX 0.968 CWF 0.64 Cp 0.582 CWA 0.82 CPF 0.56 L/B 6.65

TABLE 2 MODEL DATA Model No. 932 (Parent DTMB 4214-B4) Ship Series 60 CB = 0.80 Ship Owner MARAD ORA No. 04652 Material: Wax Model: X = 42.857 Ship LOA LWL 14.2345 ft; 170.76 in. 610.05 ft LBP 14.000 ft; 168.00 in. 600.00 ft B 2.154 ft; 25.85 in. H mean 0.862 ft; 10.340 in. fwd aft A = 1,293.5 lb at 10.34 in. Draft, 73 F 46,774 tons, S.W. W.S. bare 45.571 sq ft 83,701 sq ft rudder.362 sq ft 665 sq ft appendage Total 45.933 sq ft 84,366 sq ft Ax, LWL 1.857 sq ft Friction Basis: ATTC 1947 Aw, LWL ACf: 0.4 x 10-3 Ax/Tank Area 0.9774% Designed Speed 3.161 ft/sec V/LVW =.496; 12.25 KTS Trial Speed 3.543 ft/sec V/LWL5 = 556; 13.72 KTS MODEL TEST CONDITION Draft: Mean: 10.34 in. Aft: Fwd: Turbulence: Trip Wire Temp: MODEL CHARACTERISTICS LBP/LWL CpA 0.750 B/H 2.5 LCB, %LBP + 2.5 of, LE/LBP 0.290 CpV 0.920 LCFi/ LBP LX/LBP 0.300 CpVwF 0.971 L/V2 5.092 LR/LBP 0.410 CPVA 0.867 S/v 6.028 CB 0,80 CW 0.871 KR = R/N/H 0.118 CX 0.994 CWF 0.881 CiT 0.776 Cp 0.805 CWA 0.860 CiL CpF 0.861 L/B 6.5 1/2 0E 43

TABLE 3 PROPELLER DATA PROPELLER UM No. 4 UM No. 5 PARENT DTMB No. 3377 DTMB NO. 3566 DIAMETER (d), inches 7.230 6.658 (6.682)* PITCH (p), inches 6.977 (6.650)* 7.250 (7.062)* CHARACTERISTICS PITCH-DIAMETER RATIO, P/D.965 (.920)* 1.090 (1.057)* MEAN-WIDTH RATIO, MWR.213 EFFECTIVE AREA-DISC AREA RATIO, EA/DA.450.514 BLADE THICKNESS FRACTION, BTF.045 RAKE, DEGREES ARC 6.00 NO. OF BLADES 4 4 *Indicates values corresponding to parent propellers,

UNIVERSITY OF MICHIGAN 3 9015 03483 3759