______________ MODEL DATABASE
FOR NAVCAD
___________12.06.2001____________
CORRELATING BARE-HULL PREDICTION TO KNOWN PERFORMANCE
( 8 February 1994)
The best of these methods
have some statistical error and it is universally accepted that when
applied correctly,a
designer must typically still contend with about a five percent possible
margin of error.
·
ALIGNED PREDICTION
Perhaps
the most widely used application of aligned prediction is with the U.S. Navy’s
‘worm curve
factors’in their Taylor standard series program.This application uses the
Taylor
series as the definitive tool to evaluate the resistance characteristics of a
given
hull-in
conjunction with worm curve factors for a suitable hull to ‘realign’the Taylor
prediction.
*
Displacement,Semi-displacement,Sailing yacht and Catamaran hulls following Froude’s
Corresponding speed vs.resistance relatýonships,NAVCAD’s aligns a
prediction as follows:
Predict resistance
parameters of the model using the chosen prediction method compare
how well
the prediction fares against known results by saying the actual-to-calculated
ratios of
the parameters record these ratios versus Froude number to create a correlation
curve
Modify the
calculated prediction for the new subject hull per the correlation curve.
* Planning hulls Correlation of
the planning hulls to model/parent data is much more
complex than that for
displacement type hulls.The effect of trim contributes to an
additional variable, so
that trim also needs to be correlated,as well as resistance.The key
to the new system is in
the use of a non-dimensional scaling coefficient reflecting the
location of
the longitudinal center of planning lift or pressure.This coefficient obviously
is
sensitive
to the longitudinal center of gravity (LCG) and thus incorporates the effect
of
LCG into
the picture.Resistance and trim coefficients will need to be fit to a
coefficient of
speed.This
speed coefficient is a beam-based Froude number divided by the lift-beam
ratio.parent’s actual coefficients versus calculated coefficients form
the basis of the
Planning
hull aligned prediction in NAVCAD.
·
EXTRAPOLATION
A slightly
different wrinkle to using known performance in resistance prediction is
extrapolation.Simply described,an extrapolation predicts a vessel’s
resistance using a
‘series’of only one model.
____COMPARATOR DEMO COPY FOR ORIGINAL MODELS TO SAVÝTSKY REGRESSION
METHOD-2000_______
Savitsky regression presents a group of equations used to
determine equilibrium conditions
And vessel
resistance for hard-chine planning craft.Based on the well-established Savitsky
Equations (where
all forces pass through the center of gravity),this method determines dynamic
Trim,porpoising stability and vessel resistance.
Navcad also
incorporates and modifications made to the Savitsky method by Blount and Fox.A
method
For parameter
consistency and a multiplication factor to better evaluate the hump-speed range
has been
included.The bare hull planning resistance is determined from a complex
eqilibrium
condition of
lift,drag and trim.
This new 1260
pages sheets was prepared by Oktay Çemberci.Original 65A,65B,62,Delft model was
Compared to
Savitsky regression method.Method is good for Volumetric Froude Number 2.5 to
6.00.
____________________________________________________________________________________________________________
_____________ DISPLACEMENT SHIP MODELS ______________________________________
W. F R O U D E C A
R G O S H I P Series
Çemberci Denizcilik 08 December 1995
Model Lpp/Bwl
Lwl/Bwl Bwl/Twl Cb
Cx Lcb/Lpp Lpp/Vol
Vol/Lwl S/Vol
30 A 7.65 ---- 2.25 0.760
0.980 +1.38F 5.577
5.766 6.154 *
30 B 7.65 ---- 2.25
0.743 0.980 +0.63F
5.619 5.638 6.180 *
30 C 7.65 ---- 2.25 0.727
0.980 -0.27A 5.660
5.516 6.204 *
30 D 7.65 ---- 2.25 0.743
0.980 +0.65F 5.619 5.638 6.180 *
30 F 7.65 ---- 2.25 0.743
0.980 +0.54F 5.619
5.638 6.180 *
47 7.65 ---- 2.25 0.764
0.980 -0.39A 5.567
5.797 6.152 *
49 7.65 ---- 2.25 0.722
0.980 +1.62F 5.673
5.478 6.211 *
50 A 7.65 ---- 2.25 0.743
0.980 +0.68F 5.619
5.638 6.180 *
50 B 7.65 ---- 2.25 0.743
0.980 +0.54F 5.619
5.638 6.180 *
55 C 7.65 ---- 2.25 0.698
0.980 +1.73F 5.737
5.296 6.250 *
55 D 7.65 ---- 2.25 0.677
0.980 +0.64F 5.796
5.137 6.286 *
56 A 7.65 ---- 2.25 0.677 0.980 +0.80F
5.796 5.137 6.286 *
56 B 7.65 ---- 2.25 0.677
0.980 +0.86F 5.796
5.137 6.286 *
56 C 7.65 ---- 2.25 0.656
0.980 -0.34A 5.857
4.977 6.327 *
57 A 7.65 ---- 2.25 0.704 0.980
-0.49A 5.721 5.342
6.239 *
57 B 7.65 ---- 2.25 0.677
0.980 +0.93F 5.796
5.137 6.286 *
57 C 7.65 ---- 2.25 0.677
0.980 +0.63F 5.796 5.137
6.286 *
67 A 7.65 ---- 2.25 0.653
0.980 +2.04F 5.866
4.955 6.328 *
68 A 7.65 ---- 2.25 0.833
0.980 +1.56F 5.409
6.320 6.069 *
68 C 7.65 ---- 2.25 0.799
0.980 -0.19A 5.484
6.062 6.106 *
68 D 7.65 ---- 2.25 0.812
0.980 +0.47F 5.455
6.161 6.090 *
86 A 7.65 ---- 2.25 0.826
0.980 -0.27A 5.424
6.267 6.077 *
86 B 7.65 ---- 2.25 0.812
0.980 +0.43F 5.455
6.161 6.090 *
86 C 7.65 ---- 2.25 0.812
0.980 +0.47F 5.455
6.161 6.090 *
97 A 7.65 ---- 2.25
0.812 0.980 +0.51F
5.455 6.161 6.090 *
97 B 7.65 ---- 2.25 0.796
0.980 +1.19F 5.491
6.040 6.110 *
97 C 7.65 ---- 2.25 0.812
0.980 +0.41F 5.455
6.161 6.090 *
103 A 7.65 ---- 2.25 0.665
0.980 +1.88F 5.830
5.046 6.307 *
103 B 7.65 ---- 2.25 0.641
0.980 +0.97F 5.902
4.864 6.356 *
103 C 7.65 ---- 2.25 0.641
0.980 +0.89F 5.902
4.864 6.356 *
103 D 7.65 ---- 2.25 0.618
0.980 -0.35A 5.975
4.689 6.406 *
109 A 7.65 ---- 2.25 0.672
0.980 -0.52A 5.810
5.099 6.294 *
109 B 7.65 ---- 2.25 0.641
0.980 +0.68F 5.902
4.864 6.356 *
109 C 7.65 ---- 2.25 0.612
0.980 +2.25F 5.994
4.644 6.417 *
110 A 7.65 ---- 2.25 0.641
0.980 +1.08F 5.902
4.864 6.356 *
110 B 7.65 ---- 2.25 0.641
0.980 +0.67F 5.902
4.864 6.356 *
1069 A 7.65 ---- 2.25 0.755
0.980 +1.91F 4.716
9.535 5.662 *
1069 B 7.65
---- 2.25 0.752 0.980
+1.75F 4.722 9.497
5.666 *
1069 C 7.65 ---- 2.25 0.755
0.980 +1.85F 4.716
9.535 5.662 *
1069 D 7.65 ---- 2.25 0.752
0.980 +2.39F 4.722
9.497 5.664 *
1131 A 8.00 ---- 2.15 0.810
0.980 +1.17F 5.540
5.880 6.137 *
1131 C 8.00 ---- 2.15 0.810
0.980 +1.30F 5.540
5.880 6.137 *
1131 D 8.00 ---- 2.15 0.811
0.980 +1.30F 5.538
5.887 6.137 *
1131 E 8.00 ---- 2.15 0.804
0.980 +0.67F 5.554
5.837 6.145 *
1158 B 8.00 ---- 2.15 0.810
0.980 +1.43F 5.540
5.880 6.137 *
*
Estimated Values.Based C Values.ATTC.Ca=0
*
Literature = Methodical series of resistance experiments on ship models
The william Froude
Laboratory
T A Y L O R M O D E
L Series
Çemberci
Denizcilik
20 July 1996
Model Lpp/Bwl Lwl/Bwl Bwl/Twl Cb
Cx Cwp Lcb/Lpp Lpp/Vol Vol/Lwl S/Vol
1 13.00 ---- 2.93 0.519
0.927 ----- --?--- 9.839 1.050 7.876
2 13.91 ---- 2.93 0.519
0.926 ----- --?--- 9.845 1.048 7.886
3 10.07 ---- 2.93 0.519
0.926 ----- --?--- 8.298 1.750 7.302
4 10.77 ---- 2.93 0.592
0.926 ----- --?--- 8.302 1.748 7.307
5 7.96 ---- 2.93 0.518
0.926 ----- --?--- 7.098 2.797 6.785
6 8.52 ---- 2.93 0.593
0.926 ----- --?--- 7.098 2.796 6.786
7 6.25 ---- 2.93 0.520
0.928 ----- --?--- 6.032 4.557 6.132
8 6.68 ---- 2.93 0.592
0.926 ----- --?--- 6.037 4.544 6.194
9 5.31 ---- 2.93 0.518
0.926 ----- --?--- 5.417 6.290
5.795
10 5.68 ---- 2.93 0.592
0.926 ----- --?--- 5.417 6.292 5.891
171 5.80 ---- 3.75 0.500
0.925 0.640 --?--- 6.317 3.967 6.424
172 6.80 ---- 3.75 0.691 0.925 0.815
--?--- 6.308 3.985
6.639
173 3.90 ---- 4.50 0.463
0.925 0.605 --?--- 5.289 6.757 5.982
174 4.30 ---- 4.50 0.463 0.925 0.605
--?--- 5.645 5.559
6.171
175 5.00 ---- 4.50 0.463
0.925 0.605 --?--- 6.242 4.111 6.486
176 6.40 ---- 4.50 0.463
0.925 0.605 --?--- 7.359 2.509 6.985
177 9.80 ---- 4.50 0.459
0.925 0.602 --?--- 9.803 1.062 8.150
178 4.10 ---- 4.50 0.492
0.925 0.632 --?--- 5.357 6.505 6.095
179 4.60 ---- 4.50 0.490
0.925 0.631 --?--- 5.791 5.149 6.338
180 5.40 ---- 4.50 0.488
0.925 0.628 --?--- 6.457 3.715 6.718
181 4.10 ---- 4.50 0.535 0.925 0.628
--?--- 5.211 7.068
6.009
182 4.70 ---- 4.50 0.534
0.925 0.671 --?--- 5.711 5.369 6.299
183 5.50 ---- 4.50 0.537
0.925 0.673 --?--- 6.331 3.941 6.625
184 6.90 ---- 4.50 0.537
0.925 0.674 --?--- 7.360 2.508 7.141
185 10.60 ---- 4.50 0.538
0.925 0.675 --?--- 9.793 1.065 8.244
186 4.40 ---- 4.50 0.599
0.925 0.731 --?--- 5.258 6.880 6.199
187 5.00 ---- 4.50 0.605
0.925 0.736 --?--- 5.708 5.377 6.426
189 7.40 ---- 4.50 0.599
0.925 0.731 --?--- 7.436 2.432 7.370
190 11.30 ---- 4.50 0.605
0.925 0.736 --?--- 9.830 1.053 8.298
192 5.30 ---- 4.50 0.703
0.925 0.826 --?--- 5.644 5.561 6.400
193 6.20 ---- 4.50 0.687
0.925 0.812 --?--- 6.314 3.973 6.844
194 7.80 ---- 4.50 0.687
0.925 0.812 --?--- 7.358 2.510
7.500
195 12.00 ---- 4.50 0.682
0.925 0.807 --?--- 9.832 1.052 8.713
196 4.90 ---- 4.50 0.750
0.925 0.869 --?--- 5.242 6.943 6.215
197 5.50 ---- 4.50 0.746
0.925 0.865 --?--- 5.673 5.477 6.384
198 6.40 ---- 4.50 0.730
0.925 0.851 --?--- 6.321 3.960 6.752
199 8.10
---- 4.50 0.741 0.925 0.861
--?--- 7.359 2.510
7.365
200 12.30 ---- 4.50 0.729
0.925 0.850 --?--- 9.775 1.071 8.518
2155 8.76 ---- 3.35 0.552
0.920 0.685 --?--- 7.753
2.146 7.214
2156 8.76 ---- 3.35 0.552
0.920 0.685 --?--- 7.753 2.146 7.218
2157 8.76 ---- 3.35 0.552
0.920 0.685 --?--- 7.753 2.146 7.224
2158 8.76 ---- 3.35 0.552
0.920 0.685 --?--- 7.753 2.146 7.229
2159 8.76 ---- 3.35 0.552
0.920 0.685 --?--- 7.753 2.146 7.227
2160 8.76 ---- 3.35 0.552
0.920 0.685 --?--- 7.753 2.146 7.232
2161 8.76 ---- 3.35 0.552
0.920 0.685 --?--- 7.753 2.146 7.236
2162 8.76 ---- 3.35 0.552 0.920