Maneuvering Predictions for Fast Monohulls in Early Design Stage

2015 ◽  
Author(s):  
F.H.H.A. Quadvlieg ◽  
F. van Walree ◽  
V. Barthelemy
Keyword(s):  
High Speed ◽  
Model Tests ◽  
Design Stage ◽  
Correct Prediction ◽  
Design Assessment ◽  
Early Design ◽  
Early Design Stage ◽  
Directional Stability ◽  
Pros And Cons ◽  
The Time Domain

The present paper discusses directional stability and course keeping of fast monohulls. Model tests and CFD were used for analysis. In itself these are great tools, but in early design stage they are often perceived as too elaborate. In comparison, design verification is often carried out during model testing., However, it is not common to use these model tests for systematic variation or multiple design variations. In addition to model tests, tools for early design assessment are also pursued. By using a 3D panel method, maneuvering coefficients and subsequently directional stability are found in an earlier stage of the design. The present paper describes which methods can be used in the design stage, and some pros and cons of these methods. A method of choice is selected and an example is elaborated. The example ship is a high speed monohull (Fn=0.8) propelled by waterjets. This paper illustrates that the forces acting on the ship while performing forced motions are predicted. A next step (not in the present paper) is to solve the equations of motions in the time domain as a system of ordinary differential equations. However, in order to correctly predict the motions and trajectories, the correct prediction of forces and moments is essential

Optimum Design of Radial-Flow Impellers

1989 ◽  
Vol 203 (4) ◽  
pp. 229-232
Author(s):  
G S Ray ◽  
B K Sinha ◽  
S Majumdar
Keyword(s):  
Optimum Design ◽  
Centrifugal Force ◽  
Computer Aided Design ◽  
High Speed ◽  
Radial Flow ◽  
Design Stage ◽  
Early Design ◽  
Early Design Stage ◽  
Computer Aided ◽  
Aided Design

The paper presents a procedure of computer aided design of high-speed impellers. The configurations are obtained using programs for the strength under the influence of centrifugal force within given constraints. The method provides a tool for optimizing stresses at an early design stage.

Model Tests for the Validation of Extreme Roll Motion Predictions

2002 ◽  
Author(s):  
Walter L. Kuehnlein ◽  
K.-E. Brink
Keyword(s):  
Practical Knowledge ◽  
Rapid Development ◽  
Model Tests ◽  
Design Stage ◽  
Roll Motion ◽  
Ministry Of Education ◽  
Following Seas ◽  
Early Design Stage ◽  
Shaped Container ◽  
Motion Characteristics

At present common stability criteria are based on practical knowledge gained from the operation of ships. Therewith the assessment of ship safety against capsizing is partly determined by long-term statistics of accidents. Regulations like the IMO-Resolution A 167 do not rate the typical seakeeping characteristics of different hull form geometries. Therefore strictly speaking, these criteria are just applicable for ships of similar types as included in statistics. Rapid development in ship design calls for the determination of ship and cargo safety in regard of extreme roll motions or capsizing during early design stage. Within the ROLL-S project, which was founded by the German Federal Ministry of Education and Research, dynamic stability tests with a box shaped Container Ship and a RO-RO vessel have been performed. The performance of model tests, which are intended to serve for the validation of numerical simulation methods, put high demands on test and data acquisition techniques. The data of the waves encountered, course and position, as well as the response of the model had to be determined by model tests in order to use these data for the validation of numerical ship motion simulations. During the tests extreme roll motions of the two considered vessels could be observed in head seas and in following seas. Besides critical motion characteristics in following seas, like broaching, parametric induced roll motion effects were investigated in head sea condition. Remark: This paper should be read in conjunction with paper OMAE 2002-28297 which describes generation and transformation of the used waves.

Identification of Human Errors During Early Design Stage Functional Failure Analysis

2018 ◽  
Author(s):  
Lukman Irshad ◽  
Salman Ahmed ◽  
Onan Demirel ◽  
Irem Y. Tumer
Keyword(s):  
Failure Analysis ◽  
Human Error ◽  
System Level ◽  
Design Stage ◽  
Human Factors Engineering ◽  
Human Errors ◽  
Functional Failure ◽  
Early Design ◽  
Early Design Stage ◽  
Early Design Stages

Detection of potential failures and human error and their propagation over time at an early design stage will help prevent system failures and adverse accidents. Hence, there is a need for a failure analysis technique that will assess potential functional/component failures, human errors, and how they propagate to affect the system overall. Prior work has introduced FFIP (Functional Failure Identification and Propagation), which considers both human error and mechanical failures and their propagation at a system level at early design stages. However, it fails to consider the specific human actions (expected or unexpected) that contributed towards the human error. In this paper, we propose a method to expand FFIP to include human action/error propagation during failure analysis so a designer can address the human errors using human factors engineering principals at early design stages. To explore the capabilities of the proposed method, it is applied to a hold-up tank example and the results are coupled with Digital Human Modeling to demonstrate how designers can use these tools to make better design decisions before any design commitments are made.

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