AN INTEGRATED SHIP RE-DESIGN/MODIFICATION STRATEGY

2021 ◽  
Vol 161 (A1) ◽  
Author(s):  
A K P Patel ◽  
R Sharma
Keyword(s):  
Computer Aided Design ◽  
Modular Design ◽  
Ship Hull ◽  
Cfd Model ◽  
Hull Form ◽  
Design Modification ◽  
Technical Parameters ◽  
Computational Fluid Dynamics Cfd ◽  
Bulbous Bow ◽  
Aided Design

Herein, we present an integrated ship re-design/modification strategy that integrates the ‘Computer-Aided Design (CAD)’ and ‘Computational Fluid Dynamics (CFD)’ to modify the ship hull form for better performance in resistance. We assume a modular design and the ship hull form modification focuses on the forward module (e.g. bulbous bow) and aft module (e.g. stern bulb) only. The ship hull form CAD model is implemented with NAPA*TM and CFD model is implemented with Shipflow**TM. The basic ship hull form parameters are not changed and the modifications in some of the technical parameters because of re-designed bulbous bow and stern bulb are kept at very minimum. The bulbous bow is re-designed by extending an earlier method (Sharma and Sha (2005b)) and stern bulb parameters for re-design are computed from the experience gained from literature survey. The re-designed hull form is modeled in CAD and is integrated and analyzed with Shipflow**TM. The CAD and CFD integrated model is validated and verified with the ITTC approved recommendations and guidelines. The proposed numerical methodology is implemented on the ship hull form modification of a benchmark ship, i.e. KRISO container ship (KCS). The presented results show that the modified ship hull form of KCS - with only bow and stern modifications - using the present strategy, results into resistance and propulsive improvement.

An Integrated Ship Re-Design/Modification Strategy

2019 ◽  
Vol 161 (A1) ◽  
Keyword(s):  
Computer Aided Design ◽  
Modular Design ◽  
Ship Hull ◽  
Cfd Model ◽  
Hull Form ◽  
Design Modification ◽  
Technical Parameters ◽  
Computational Fluid Dynamics Cfd ◽  
Bulbous Bow ◽  
Aided Design

Herein, we present an integrated ship re-design/modification strategy that integrates the ‘Computer-Aided Design (CAD)’ and ‘Computational Fluid Dynamics (CFD)’ to modify the ship hull form for better performance in resistance. We assume a modular design and the ship hull form modification focuses on the forward module (e.g. bulbous bow) and aft module (e.g. stern bulb) only. The ship hull form CAD model is implemented with NAPA*TM and CFD model is implemented with Shipflow**TM. The basic ship hull form parameters are not changed and the modifications in some of the technical parameters because of re-designed bulbous bow and stern bulb are kept at very minimum. The bulbous bow is re-designed by extending an earlier method (Sharma and Sha (2005b)) and stern bulb parameters for re-design are computed from the experience gained from literature survey. The re-designed hull form is modeled in CAD and is integrated and analyzed with Shipflow**TM. The CAD and CFD integrated model is validated and verified with the ITTC approved recommendations and guidelines. The proposed numerical methodology is implemented on the ship hull form modification of a benchmark ship, i.e. KRISO container ship (KCS). The presented results show that the modified ship hull form of KCS - with only bow and stern modifications - using the present strategy, results into resistance and propulsive improvement.

scholarly journals OPTIMISATION OF HULL FORM OF OCEAN-GOING TRAWLER

Brodogradnja ◽  
2021 ◽  
Vol 72 (4) ◽  
pp. 33-46
Author(s):  
Cheng Zhao ◽  
◽  
Wei Wang ◽  
Panpan Jia ◽  
Yonghe Xie ◽  
...  
Keyword(s):  
Computer Aided Design ◽  
Free Form ◽  
Deformation Method ◽  
Nsga Ii ◽  
Hull Form ◽  
Free Form Deformation ◽  
Before And After ◽  
Computational Fluid Dynamics Cfd ◽  
Bulbous Bow ◽  
Aided Design

This paper proposes a method for optimising the hull form of ocean-going trawlers to decrease resistance and consequently reduce the energy consumption. The entire optimisation process was managed by the integration of computer-aided design and computational fluid dynamics (CFD) in the CAESES software. Resistance was simulated using the CFD solver and STAR-CCM+. The ocean-going trawler was investigated under two main navigation conditions: trawling and design. Under the trawling condition, the main hull of the trawler was modified using the Lackenby method and optimised by NSGA-II algorithm and Sobol + Tsearch algorithm. Under the design condition, the bulbous bow was changed using the free-form deformation method, and the trawler was optimised by NSGA-Ⅱ. The best hull form is obtained by comparing the ship resistance under various design schemes. Towing experiments were conducted to measure the navigation resistance of trawlers before and after optimisation, thus verifying the reliability of the optimisation results. The results show that the proposed optimisation method can effectively reduce the resistance of trawlers under the two navigation conditions.

Geometrical Variation and Distortion of Ship Hull Forms

2003 ◽  
Vol 40 (04) ◽  
pp. 239-248
Author(s):  
Ebru Narh ◽  
Kadir Sariöz
Keyword(s):  
Computer Aided Design ◽  
Ship Hull ◽  
Hydrodynamic Performance ◽  
Hull Form ◽  
Nonlinear Distortions ◽  
Form Design ◽  
Hull Form Design ◽  
Geometrical Variation ◽  
Hull Forms ◽  
Aided Design

Because of the risk involved with starting the hull form design from scratch, the designer most frequently initiates the hull form design process with a parent form that has satisfactory hydrodynamic performance. Hence, linear and nonlinear variation and distortion techniques have found wide applications in the hull form design studies. Some of these methods are simple and easy to apply by practicing naval architects, whereas others may be considered too complicated and difficult to use without simplifications. Existing and emerging techniques to distort a parent ship hull form are discussed and applied to a typical ship form. These techniques range from a simple one minus prismatic method to complex nonlinear distortions and include emerging computer-aided design (CAD) methods, such as shape averaging. The applications indicate that the techniques presented can be safely applied to conventional ship hull forms. The advantages and drawbacks of these methods are discussed, and numerical results are presented.

Novel Active Inflow Control Technology for Optimized Flow and Reduced Intervention

2021 ◽  
pp. 1-12
Author(s):  
Ashutosh Dikshit ◽  
Vivek Agnihotri ◽  
Mike Plooy ◽  
Amrendra Kumar ◽  
Seymur Gurbanov ◽  
...  
Keyword(s):  
Flow Control ◽  
Computer Aided Design ◽  
Process Development ◽  
Horizontal Wells ◽  
Field Trials ◽  
Control Device ◽  
Computational Fluid Dynamics Cfd ◽  
Inflow Control Device ◽  
Aided Design ◽  
Subsequent Intervention

Summary Integrating a flow control sliding sleeve into a sand screen can provide multiple advantages to the user in controlling the production inflow, but it comes with an increased completion cost as well as an increase in the number of interventions required when it is time to operate those valves. Especially in long horizontal wells, this can become time-consuming and inefficient. A few technologies exist to address this issue, but they either are too complex or require specialized rigging equipment at the wellsite, which is not desirable. As described herein, a unique, fit-for-application modular sliding sleeve sand screen assembly with dissolvable plugs was developed that eliminates the need for washpipe during run-in-hole (RIH) and allows flow control from several screens by means of a single sliding sleeve door (SSD), thereby also optimizing the subsequent intervention operations by reducing the number of SSDs in the well. The design and field installation of these modular screens is presented in this paper. The new modular sand screen consisted of an upper joint, modular middle joint, modular middle joint with an inflow control device (ICD) integrated into an SSD (with optional dissolvable plugs), a lower joint, and novel field-installable flow couplings between them. The design allows for any number of non-ICD/SSD screen joints to be connected to any number of ICD/SSD joints in any order. A computer-aided design was followed to achieve all the operational and mechanical requirements. Computational fluid dynamics (CFD) was used to optimize the flow performance characteristics. Prototypes were manufactured and tested before conducting successful field trials. The design process, development, and field installation results are presented herein.

Dimensional Measurement of a Composite Ship Hull Using Coherent Laser Radar Yielding Submillimeter Results

2004 ◽  
Vol 20 (04) ◽  
pp. 232-239
Author(s):  
Steven D. Hand ◽  
David B. Ober ◽  
Bryan A. Bond ◽  
Edward A. Devine
Keyword(s):  
Computer Aided Design ◽  
Focal Length ◽  
Ship Hull ◽  
Laser Radar ◽  
Dimensional Measurement ◽  
Reinforced Plastic ◽  
Fiberglass Composite ◽  
Coherent Laser Radar ◽  
Composite Ship ◽  
Aided Design

The use and result of coherent laser radar as a noncontact method for the dimensional measurement of a ship hull is described. The hull, keel, and deck of a halfscale notional glass-reinforced plastic (fiberglass) composite hull test specimen are measured to submillimeter accuracy and then compared to the computer-aided design (CAD) model for conformance validation. Positives and negatives of this technology are the subject of this paper and include the high accuracy potential of the coherent laser radar, the minimal manpower requirements needed to achieve accurate results, and the limitation of the equipment's digital focal length and its effects on setup and data acquisition.

scholarly journals Computational Evaluation of Surgical Design for Multisegmental Complex Congenital Tracheal Stenosis

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Limin Zhu ◽  
Xiaolei Gong ◽  
Jinlong Liu ◽  
Youjin Li ◽  
Yumin Zhong ◽  
...  
Keyword(s):  
Tracheal Stenosis ◽  
Computer Aided Design ◽  
Surgical Correction ◽  
Patient Specific ◽  
Congenital Tracheal Stenosis ◽  
Computational Evaluation ◽  
Life Threatening ◽  
Computational Fluid Dynamics Cfd ◽  
Aerodynamic Parameters ◽  
Aided Design

Multisegmental complex congenital tracheal stenosis (CTS) is an uncommon but potentially life-threatening malformation of the airway. Staged surgery is indicated for the complex pathophysiology of the abnormal trachea. Surgical intervention to fix the stenotic segments may result in different postoperative outcomes. However, only few studies reported the design of surgical correction for multisegmental CTS. We used computer-aided design (CAD) to simulate surgical correction under different schemes to develop a patient-specific tracheal model with two segmental stenoses. Computational fluid dynamics (CFD) was used to compare the outcomes of different designs. Aerodynamic parameters of the trachea were evaluated. An obvious interaction was found between the two segments of stenosis in different surgical designs. The surgical corrective order of stenotic segments greatly affected the aerodynamic parameters and turbulence flows downstream of tracheal stenosis and upstream of the bronchus. Patient-specific studies using CAD and CFD minimize the risk of staged surgical correction and facilitate quantitative evaluation of surgical design for multiple segments of complex CTS.

scholarly journals Design and Analyses of a Transdermal Drug Delivery Device (TD3) †

Sensors ◽  
2019 ◽  
Vol 19 (23) ◽  
pp. 5090 ◽  
Author(s):  
Jennifer García ◽  
Ismael Ríos ◽  
Faruk Fonthal Rico
Keyword(s):  
Drug Delivery ◽  
Transdermal Drug Delivery ◽  
Computer Aided Design ◽  
Micro Electro Mechanical System ◽  
Discharge Process ◽  
Microneedle Array ◽  
Delivery Device ◽  
Drug Delivery Device ◽  
Computational Fluid Dynamics Cfd ◽  
Aided Design

In this paper, we introduce a novel type of transdermal drug delivery device (TD3) with a micro-electro-mechanical system (MEMS) design using computer-aided design (CAD) techniques as well as computational fluid dynamics (CFD) simulations regarding the fluid interaction inside the device during the actuation process. For the actuation principles of the chamber and microvalve, both thermopneumatic and piezoelectric principles are employed respectively, originating that the design perfectly integrates those principles through two different components, such as a micropump with integrated microvalves and a microneedle array. The TD3 has shown to be capable of delivering a volumetric flow of 2.92 × 10−5 cm3/s with a 6.6 Hz membrane stroke frequency. The device only needs 116 Pa to complete the suction process and 2560 Pa to complete the discharge process. A 38-microneedle array with 450 µm in length fulfills the function of permeating skin, allowing that the fluid reaches the desired destination and avoiding any possible pain during the insertion.

Prometheus: A Geometry-Centric Optimization System for Combustor Design

2014 ◽  
Author(s):  
Xu Zhang ◽  
David J. J. Toal ◽  
Neil W. Bressloff ◽  
Andy J. Keane ◽  
Frederic Witham ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Gas Turbine ◽  
Computer Aided Design ◽  
Design System ◽  
Gas Turbine Combustor ◽  
Computer Aided ◽  
Computational Fluid Dynamics Cfd ◽  
Automatic Mesh ◽  
Aided Design

The following paper presents an overview of the Prometheus design system and its applications to gas turbine combustor design. Unlike a traditional “optimizer-centric” method, Prometheus aims to reduce both the level of workflow complexity and rework by taking a more “geometry-centric” approach to design optimization by shifting the control of script generation away from the optimization program to the computer aided design (CAD) package. Prometheus therefore enables significant geometry changes to be automatically reflected in all subsequent scripts necessary for the analysis of a combustor. Prometheus’ current capabilities include automatic fluid volume generation and aero-thermal and thermo-acoustic network generation as well as automatic mesh and computational fluid dynamics (CFD) script generation.

scholarly journals Ask the Supercomputer

2006 ◽  
Vol 128 (04) ◽  
pp. 36-38
Author(s):  
Jean Thilmany
Keyword(s):  
Computer Aided Design ◽  
Research Work ◽  
Associate Professor ◽  
Complex Flows ◽  
Heart Pump ◽  
Model Complex ◽  
Computational Fluid Dynamics Cfd ◽  
Rice University ◽  
And Performance ◽  
Aided Design

This paper analyzes research work on developing techniques to study complex fluids. Although several computational fluid dynamics (CFD) vendors now sell desktop software that mechanical engineers can buy to model complex flows, many problems are still simply too hard for those applications. According to engineers, CFD programs for these complex problems can take years to write, even with the supercomputer's aid. Moreover, some flows may never be modeled: they are just too complex for even the most advanced software. Behr and a colleague, Matteo Pasquali, an Associate Professor in the Department of Chemical and Biomolecular Engineering at Rice University, are now at work writing a CFD application that will help a heart-pump manufacturer analyze how blood would move through different configurations of the pump. Pasquali and Behr spent two years trying to turn the pump geometry and performance data Baylor provided into usable data. They converted the pump's computer-aided design information and input it into their homegrown CFD program, then came up with software tools to rotate one part of the computationally meshed pump element with respect to another.

Cogging Torque Reduction in Permanent Magnet Brushless DC Motor by using Various Design Modification Techniques

2020 ◽  
Vol 12 (2) ◽  
Author(s):  
M. Arun Noyal Doss ◽  
A. Ananthi Christy ◽  
Aishwarya Manibala Jha ◽  
Abhishek Iyer ◽  
R. Varun
Keyword(s):  
Computer Aided Design ◽  
Brushless Dc Motor ◽  
Bldc Motor ◽  
Element Analysis ◽  
Design Modification ◽  
Cogging Torque ◽  
Brushless Dc ◽  
Permanent Magnet Brushless Dc ◽  
Torque Values ◽  
Aided Design

Cogging torque is a problem for continuous motion applications like scanning, contouring and mainly positioning applications that requires smooth and accurate motion. It degrades the performance and the life of the motor. Cogging torque cannot be completely omitted but can be reduced drastically using various design modification techniques. This paper focuses on reducing cogging torque in BLDC using three different techniques like stator slot modification, rotor magnet modification and skewing of stator slots and rotor magnets. The result obtained by combining these three techniques has yielded a new model with reduced cogging torque and trapezoidal Back Electromotive Force as compared to the conventional BLDC motor. Also, the cogging torque values for different rotor magnets and stator slots shapes are calculated and studied using Finite Element Analysis (FEA). A detailed thermal analysis of the same model presents the temperature and heat flow plots using Computer Aided Design (CAD).

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