FORMDATA Series. Characteristics of the FORMDATA series

Transcription

1 Appendix B 525 FORMDATA Series The systematic series of FORMDATA of the Technical University, Denmark, Lyngby (Copenhagen Denmark) is still considered today as the most complete of the public domain series and responds well to the hull form requirements of modern merchant ships. It has been developed based on the systematic analysis of the geometric data of series of existing ships of the 60ties and of earlier systematic series, considering, also, their calm water hydrodynamics (resistance). The FORMDATA series provides data both for the determination of the hydrostatic/stability characteristics of the ship during the preliminary design stage, before finalizing the ship lines, and for the required propulsive power (see, Guldhammer and Harvald 1974). In contrast to the previously elaborated series of Lap and Series 60, the present systematic series provides in a systematic way the ordinates of sections (offsets) in dimensionless percentages of the beam and of the reference draft; that is, there is no need to develop the ship sections on the basis of determined sectional areas, but their form is given in proper scale; this greatly reduces the effort spent for the drafting of the ship lines. Characteristics of the FORMDATA series 1. It refers to ships with vertical sides at the midship section. The recommended midship section coefficients ( C M = 0.74 ~ 0.995) are shown in the following figure and are arranged according to the numbers 1 to 6 (Fig. B.10). 2. Three basic section forms are offered: sections of strong U character (full lines of U shape), V type sections (shape V) and N type sections (normal sections, without pronounced character).

2 526 Appendix Fig. B.10 Corresponding code number of midship section coefficient C M Fig. B.11 a Profile of conventional cruiser stern associated to U, N, V sectional forms. b Profile of conventional bow associated to U, N, V forms 3. The above U, V and N sections are combined with two sets of stern A (aft) and bow F (forward) sections. 4. The configuration of the bow and stern is in principle possible in conventional manner (U, V and N forms) (see Fig. B.11). Also, various types of bulbous bow

3 Appendix B 527 Fig. B.12 a Profile of bow forms B (bulbous bow). b Profile of stern forms C (transom stern) (symbol B), transom stern (symbol C 1 ), or conventional cruiser stern (symbol: T), are offered (see Fig. B.12). 5. Every set of the given curves is encoded by a combination of symbols and numbers, consisting of three characters, and sometimes in addition with one index, e.g. U2 F, B 0 1 F, Τ Β 2Α. Explanations The first character of section s symbol: it refers to the type of sections, of bow (U, N, V) and stern (C, T). The second character (number): refers to the corresponding C M (see Fig. B.10). Occasional index (number 0, 4, 5, 8, 10 to the character B) denotes the ratio of bulbous area at F.P. to the area Α Μ. Occasional index (symbol of A, B, C, D to the letter C): denotes the relative slope of the transom stern against the vertical position (index D). The third character (symbol A or F): is a reference to the aft- or fore-body of the vessel. 1 The symbols C (transom stern) and T (cruiser stern) can be easily mistaken and applied just the other way around, namely C for cruiser stern and T for transom stern. However, here the original definition by Guldhammer, who refers to the cruiser stern as that for tankers and hence this symbol T is maintained.

4 528 Appendix Application Procedure 1. Selection of the fore and aft-body block coefficients based on the known C B and LCB (longitudinal distance of the center of buoyancy from the middle section, + means abaft of midship). C BF = C B ( LCB/L PP ) C BA = C B ( LCB/L PP ) Based on the coefficients C ΒF and C ΒΑ, it is possible to select a combination of the character of the fore-body and aft-body sections. In the following Tables B.1 and B.2, the feasible fore-body forms are indicated in the first row, in the second row the corresponding values of C BF, while in the first column the possible aft-body forms are listed with the corresponding coefficients C BA. The values shown in the table, which cross-connecting possible combinations of fore- and aft-body, concern the limits of variation of C B (first row) and of LCB (% L PP -second row). 2. Typical set of curves of the FORMDATA series for various combinations of C M, C B, type of sections and the bow/stern, are given in the following figures. The complete set of FORMDATA curves is given in the following reference: H. E. Guldhammer, FORMDATA Ι V, Danish Technical Press, 1962 (FOR- MDATA Ι: various forms), 1963 (FORMDATA ΙΙ: full and fine ships), 1967 (FORMDATA ΙΙΙ: tanker and bulbous bow ships), 1969 (FORMDATA IV: fishing boats series). 3. Limits of application of the series (Figs. B.13, B.14, B.15, B.16, B.17, B.18, B.19, B.20, B.21, B.22, B.23, B.24, B.25, B.26, B.27 and B.28): C C C B M WP = = =

5 Appendix B Table B.1 Combinations of cruiser stern and bulbous bow of the FORMDATA series according to Guldhammer 529

6 530 Table B.2 Combinations of cruiser stern and non-bulbous bow of the FORMDATA series according to Guldhammer SECTIONS SERIES T1A U1A U2A N2A V2A U3A N3A V3A N4A CBA CBF U1F U2F N2F V2F U3F N3F V3F N4F Appendix

7 Appendix B Fig. B.13 Dimensionless sections T1A-FORMDATA for stern section of U type, series of tankers (T: tanker), cruiser C M = 0,995 and C BA =

8 532 Fig. B.14 Dimensionless sections UlA-FORMDATA for stern section of U type, C M = and C BA = Appendix

9 Appendix B Fig. B.15 Dimensionless sections of B 5 lf-formdata for bulbous bow section, bulb area 5 % A M, C M = and C BF =

10 534 Fig. B.16 Dimensionless sections of B 10 lf-formdata for bulbous bow section, bulb area 10 % A M, C M = and C BF = Appendix

11 Appendix B Fig. B.17 Dimensionless sections U2A-FORMDATA for stern section of U type, C M = 0.98 and C BA =

12 536 Fig. B.18 Dimensionless sections N2A-FORMDATA for stern section of N type, C M = 0.98 and C BA = Appendix

13 Appendix B Fig. B. 19 Dimensionless sections V2A-FORMDATA for stern section of V type, C M = 0.98 and C BP =

14 538 Fig. B.20 Dimensionless sections U2F-FORMDATA for bow section of U type, C M = 0.98 and C BF = Appendix

15 Appendix B Fig. B.21 Dimensionless sections N2F-FORMDATA for bow section of N type, C M = 0.98 and C BF =

16 540 Fig. B.22 Dimensionless sections V2F-FORMDATA for bow section of V type, C M = 0.98 and C BF = Appendix

17 Appendix B Fig. B.23 Dimensionless sections B 4 2F-FORMDATA for bulbous type bow, bulb area 4 % A M, C M = 0.98 and C BF =

18 542 Fig. B.24 Dimensionless sections B 8 2F-FORMDATA for bulbous type bow, bulb area 8 % A M, C M = 0.98 and C BF = Appendix

19 Appendix B Fig. B.25 Dimensionless sections C A 2A-FORMDATA for stern section of transom type with slope A, C M = 0.98 and C BA =

20 544 Fig. B.26 Dimensionless sections C B 2A-FORMDATA for stern section of transom type with slope B, C M = 0.98 and C BA = Appendix

21 Appendix B Fig. B.27 Dimensionless sections C C 2A-FORMDATA for stern section of transom type with slope C, C M = 0.98 and C BA =

22 546 Fig. B.28 Dimensionless sections C D 2A-FORMDATA for stern section of transom type with slope D, C M = 0.98 and C BA = Appendix