A Resistance Study on a Systematic Series of Low L/B Vessels

1993 ◽  
Vol 30 (04) ◽  
pp. 286-296
Author(s):  
Sander M. Calisal ◽  
Dan McGreer
Keyword(s):  
West Coast ◽  
Resistance Test ◽  
Series Data ◽  
Test Results ◽  
Fishing Vessel ◽  
Hull Form ◽  
Small Vessels ◽  
Design Speed

Model resistance test results for a systematic series of low L/B, displacement-type vessels are presented. The UBC Series is based on West Coast seiners and trawlers. These vessels have low L/B and L/V⅓ values that are outside the range of existing model series data. A parent hull form was developed that has 14 percent less resistance and yet has the same displacement and deck area of a typical fishing vessel. A series of 13 models was generated by systematically varying L/B, B/T and Cb. Algorithms are presented for calculation of the resistance of similar small vessels for two loading drafts. Results of side bulb applications reduced the resistance of the parent hull at design speed by an additional 16.6 percent. The parent hull form is designed as a developable hull form.

scholarly journals Estimation of Maneuverability of Trawl Fishing Vessel Using an Analytical Method

2021 ◽  
Vol 9 (8) ◽  
pp. 854
Author(s):  
Su-Hyung Kim ◽  
Chun-Ki Lee
Keyword(s):  
Regression Analysis ◽  
Empirical Formula ◽  
Estimation Error ◽  
Design Stage ◽  
Test Results ◽  
Fishing Vessel ◽  
Empirical Formulas ◽  
Hull Form ◽  
Fishing Vessels ◽  
Trawl Fishing

Most fishing vessels are less than 100 m in length between the perpendiculars, for which adherence to the International Maritime Organization maneuverability standards are not mandatory. In the design stage of fishing vessels, maneuverability is estimated using empirical formulas—mainly analytical methods—rather than costly and time-consuming model tests. However, the empirical formula is developed through the process of regression analysis on the model test results from merchant ships’ hull form and applying the same to the fishing vessels’ hull form may result in an estimation error due to the differences in the vessels’ characteristics—e.g., L/B, B/d and Cb·B/L—. In a previous study, the authors of this paper derived a modified empirical formula by adding the hull form parameters of trawl fishing vessels to the existing empirical formula based on those of merchant ships. This study analyzes the validity of the modified empirical formula in depth by applying it to a newly-built training vessel that has the hull form of a trawl fishing vessel. As a result of the study, the estimation results were improved by including the parameters of the hull form of trawl fishing vessels in the empirical formula developed for merchant ships.

scholarly journals Estimation of Maneuverability of Fishing Vessel Considering Hull-Form Characteristics

2021 ◽  
Vol 9 (6) ◽  
pp. 569
Author(s):  
Su-Hyung Kim ◽  
Chun-Ki Lee ◽  
Sang-Min Lee
Keyword(s):  
Model Test ◽  
Empirical Formula ◽  
Design Stage ◽  
Test Results ◽  
Fishing Vessel ◽  
Empirical Formulas ◽  
Estimation Errors ◽  
Hull Form ◽  
Fishing Vessels ◽  
Ship Maneuverability

Fishing vessels with a length (LBP) of less than 100 m are generally not required to comply with the mandatory IMO Ship Maneuverability Standards. Therefore, an analytical method using empirical formula is preferred rather than a model test, which consumes a lot of time and monetary resources in estimating the maneuverability at the design stage. However, most empirical formulas have been derived from the model test results of merchant ships, and in the process, estimation errors may occur when hull-form parameters (L/B or CbB/L) with high correlation are applied to fishing vessel hull form whose characteristics are different from those of merchant ships. Therefore, a modified empirical formula was derived from previous research by including major parameters of fishing vessel hull form in the Kijima 90 empirical formula. In this study, maneuverability of stern trawler hull form is estimated for validating a modified empirical formula. The study confirmed that including characteristic parameters of the fishing vessel hull form in the empirical formula developed for merchant ships could improve the accuracy of estimation.

scholarly journals Ex vivo evaluation of a multilayered sealant patch for watertight dural closure: cranial and spinal models

2021 ◽  
Vol 32 (8) ◽  
Author(s):  
A. Kinaci ◽  
S. van Thoor ◽  
S. Redegeld ◽  
M. Tooren ◽  
T. P. C. van Doormaal
Keyword(s):  
Ex Vivo ◽  
Resistance Test ◽  
Burst Pressure ◽  
Cerebrospinal Fluid Leakage ◽  
Computer Assisted ◽  
Dural Defect ◽  
Test Results ◽  
Physiological Conditions ◽  
Dural Attachment ◽  
The Mean

AbstractCerebrospinal fluid leakage is a frequent complication after cranial and spinal surgery. To prevent this complication and seal the dura watertight, we developed Liqoseal, a dural sealant patch comprising a watertight polyesterurethane layer and an adhesive layer consisting of poly(DL-lactide-co-ε-caprolactone) copolymer and multiarmed N-hydroxylsuccinimide functionalized polyethylene glycol. We compared acute burst pressure and resistance to physiological conditions for 72 h of Liqoseal, Adherus, Duraseal, Tachosil, and Tisseel using computer-assisted models and fresh porcine dura. The mean acute burst pressure of Liqoseal in the cranial model (145 ± 39 mmHg) was higher than that of Adherus (87 ± 47 mmHg), Duraseal (51 ± 42 mmHg) and Tachosil (71 ± 16 mmHg). Under physiological conditions, cranial model resistance test results showed that 2 of 3 Liqoseal sealants maintained dural attachment during 72 hours as opposed to 3 of 3 for Adherus and Duraseal and 0 of 3 for Tachosil. The mean burst pressure of Liqoseal in the spinal model (233 ± 81 mmHg) was higher than that of Tachosil (123 ± 63 mmHg) and Tisseel (23 ± 16 mmHg). Under physiological conditions, spinal model resistance test results showed that 2 of 3 Liqoseal sealants maintained dural attachment for 72 hours as opposed to 3 of 3 for Adherus and 0 of 3 for Duraseal and Tachosil. This novel study showed that Liqoseal is capable of achieving a strong watertight seal over a dural defect in ex vivo models.

A Design Guide for Estimating Speed Made Good for a Sailing Yacht

1981 ◽  
Author(s):  
Deborah W. Berman
Keyword(s):  
Numerical Data ◽  
Quantitative Information ◽  
Test Results ◽  
Standard Series ◽  
Hull Form ◽  
Design Guide ◽  
Current Design ◽  
Sailing Yacht ◽  
Pencil And Paper ◽  
Selection Of

This study develops a simplified comparative procedure for use in preliminary yacht design to predict Equilibrium sideforce, resistance, leeway angle and speed made good to windward for a canoe hull sailing yacht within specific form parameters on any of five standard series keels. These forces, angles and speeds are predicted for any yacht hull resembling one of nine models - ranging from light to medium-heavy length to displacement ratio - (190 to 351) - of the Delft Systematic Series for which there is numerical data. The forces are calculated at speed to length ratio of 1. 3 and heel angle of 30° to enable the designer to make use of existing comparative sail plan and rigging data. The five keels of varying aspect and area ratio, spanning current design practice, are part of a matrix developed at the Davidson Laboratory. In this paper, a canoe yacht hull form similar to Model 7 of the Delft Series is tank tested on 3 Standard Series keels and compared to results obtained from testing a 5.5 m hull, which is similar to Model 8, on the same keels. A prediction procedure is developed and checked against test results. A few Equations, selected values from included tabulations, a calculator, pencil and paper will yield quantitative information for the yacht designer in the selection of a keel for the hull of a sailing yacht.

Risk Assessment of Small Fishing Vessel Trap Net Operations

1995 ◽  
Vol 32 (03) ◽  
pp. 231-243
Author(s):  
Todd Schauer ◽  
Barry Romberg ◽  
Changben Jiang ◽  
Armin W. Troesch
Keyword(s):  
Native American ◽  
Nonlinear Dynamic System ◽  
Line Tension ◽  
Operating Conditions ◽  
Fishing Vessel ◽  
Moment Curve ◽  
Upper Great Lakes ◽  
Small Vessels ◽  
Increased Risk ◽  
Nonlinear Rolling

This paper describes a means by which the capsize risk associated with various fishing vessel operating conditions can be evaluated. Rather than relying on the static restoring moment curve as the primary criteria for vessel safety, modern nonlinear systems analysis is applied to the problem of extreme nonlinear rolling in random beam sea. While the method is quite general and not limited to small vessels, it is illustrated with a specific application involving Native American trap net fishing on the upper Great Lakes. General trap net operations, as practiced by Native American fishermen and women in the Grand Traverse Bay region, are presented in detail. The most significant characteristic of trap net operations is the heel induced during net deployment and net lifting. The increased risk to the vessel, in terms of the increased probability of capsize is quantified for various heel angles and various sea states. A significant advantage of the capsize analysis method presented here is its ability to investigate quickly the effects of many parameters (e.g., trap net line tension, wave height, and/or wave period) on a nonlinear dynamic system without having to resort to extensive simulation studies.

Optimization of the Hybrid Ship Transport Factor through Retrofitted Wave Cancelling Side-Hull Expansions and Bow Bulb

2015 ◽  
Author(s):  
Manivannan Kandasamy ◽  
Ping C. Wu ◽  
Scott Bartlett ◽  
Loc Nguyen ◽  
Frederick Stern
Keyword(s):  
High Performance ◽  
Negative Impact ◽  
Fiscal Year ◽  
Hull Form ◽  
Transport Factor ◽  
Resistance Reduction ◽  
The Us ◽  
Us Navy ◽  
Speed Range ◽  
Design Speed

The US Navy is currently considering the introduction of a Flight III variant beginning with DDG-123 in Fiscal Year 2016. The new design incorporates a new combat system and associated power and cooling upgrades. The overall system improvements increase the payload of the ship and the resulting increased displacement has a negative impact on the service life allowance for range, fuel consumption and sea-keeping characteristics. The present objective is to increase the hull displacement without resistance and sea-keeping penalty and with minimal modifications to the baseline DTMB-5415 design (open literature surrogate of the existing DDG-51 hull form) by using retrofitted blisters in the form of side hull expansions and a bow-bulb. The investigation makes use of high-performance CFD computing for analysis of wave cancellation mechanisms. A candidate modified 5415 design with both blisters and bow bulb shows a resistance reduction of ~11% w.r.t.the baseline 5415 in the design speed range of 15-19 knots, even though the displacement is increased by 8%, such that the transport factor is increased by 19%.

scholarly journals Hull Form Improvements of Fishing Vessel by Non-protruding Bow Bulb

1992 ◽  
Vol 1992 (171) ◽  
pp. 53-60
Author(s):  
Kazuo Suzuki ◽  
Sander M. Calisal ◽  
Masahiro Tamashima
Keyword(s):  
Fishing Vessel ◽  
Hull Form

scholarly journals The Nexus between Export and Economic Growth in Tanzania

2019 ◽  
Vol 1 (2) ◽  
pp. p95
Author(s):  
Romanus L. Dimoso (PhD, Economics) ◽  
UTONGA, Dickson (MSc. Economics)
Keyword(s):  
Economic Growth ◽  
Time Series Data ◽  
Series Data ◽  
Test Results ◽  
Causality Test ◽  
Goods And Services ◽  
Long Run ◽  
Causality Tests ◽  
The Government ◽  
Econometrics Analysis

This study explored the causal relationship between exports and economic growth in Tanzania. It analyzed time series data for the period of 1980 to 2015. Economic growth is measured in terms of growth per cent while exports are measured in percentage change of goods and services sold abroad. Econometrics analysis was employed in the due course. Such procedures as testing for the presence of unit root, co-integration and causality were done. Furthermore, the Johansen co-integration and Granger causality tests were employed to examine the long-run relationship among variables. The results of co-integration indicate the existence of one co-integrating equation. The causality test results exhibited causality which runs from economic growth to exports. The results conclude that, in the long run, there is a relationship between exports and economic growth in Tanzania. This study recommends the Government to make efforts to improve exports and eventually, in the long-run, rejuvenating the economy.

scholarly journals ANALISIS FAKTOR-FAKTOR YANG MEMPENGARUHI IMPOR BERAS DI INDONESIA

2019 ◽  
Vol 11 (2) ◽  
pp. 183-201
Author(s):  
Yona Namira ◽  
Iskandar Andi Nuhung ◽  
Mudatsir Najamuddin
Keyword(s):  
Time Series ◽  
Linear Regression ◽  
Multiple Linear Regression ◽  
Time Series Data ◽  
Series Data ◽  
Test Results ◽  
The Us ◽  
Rice Prices ◽  
Us Dollar ◽  
Spss Software

This study aims to 1) identify factors that affect the import of rice in Indonesia 2) analyze the influence of these factors on imports of rice in Indonesia. The data used in this research are time series data from 1994 to 2013 from the Central Statistics Agency (BPS), the Ministry of Agriculture, Ministry of Commerce, National Logistics Agency (Bulog), and Bank Indonesia. Multiple linear regression through SPSS software version 21 was employed to analyze the data. The test results together indicated the variables of productions, consumptions, stocks of rice, domestic rice prices, international rice prices and the rupiah against the US dollar affect the imports of rice in Indonesia.

A Fishing Vessel Energy Analysis Program

1989 ◽  
Vol 26 (01) ◽  
pp. 62-73
Author(s):  
Sander M. Calisal ◽  
Dan McGreer ◽  
Gerry F. Rohling
Keyword(s):  
Fuel Consumption ◽  
Return On Investment ◽  
Energy Analysis ◽  
Fuel Saving ◽  
Analysis Program ◽  
Fishing Vessel ◽  
Small Vessels ◽  
University Of British Columbia ◽  
Propeller Design ◽  
The University

A microcomputer-based program has been developed at the University of British Columbia to help fisherman and naval architects estimate fishing vessel fuel consumption. The program allows users to calculate the fuel consumption for a given fishing trip scenario. The program can then be used to calculate the return on investment of fuel saving improvements made to the vessel such as: Kort nozzle, two speed gearbox, variable-pitch propeller, and new propeller design. The program can be used for the design of small vessels such as tugs and supply vessels.

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