New Promising Generation of Twin-Gondola LNG Carriers Optimized with the Aid of CFD Calculations

2005 ◽  
Author(s):  
Henk V. Valkhof ◽  
Eduardo Minguito ◽  
Klaas Kooiker
Keyword(s):  
Viscous Flow ◽  
Far East ◽  
Point Of View ◽  
Maximum Efficiency ◽  
Hull Form ◽  
Overall Design ◽  
Computational Fluid Dynamics Cfd ◽  
New Generation ◽  
Hydrodynamic Optimization ◽  
Adequate Design

As natural gas is becoming an important energy source, a large fleet is needed to transport it in liquefied form across the oceans in specially designed LNG carriers from mainly the Middle East towards the Far East. During the overall design process of such a vessel the shape of the hull form and its propulsors play an important role from a hydrodynamic point of view. This paper describes the design of a twin-gondola LNG carrier for Navantia. The twingondola aft body has proven to be an adequate design concept, but due to the complexity of the flow around the aft body the design should be carried out with great care. Computational Fluid Dynamics (CFD) tools are extremely valuable in the hydrodynamic optimization process of the hull. In this design both potential flow codes and viscous flow codes have been used to obtain the optimum hull form. With the results of the PARNASSOS viscous flow calculations it was possible to make decisions with regard to the horizontal angle and the inclination of the gondolas, and the slope of the buttocks in the area between the gondolas. Special attention has been paid to avoid flow separation around the aft body. The gondolas have been oriented in such a way that maximum efficiency is achieved. The performance of the resulting design has been verified by model tests in MARIN’s Deep Water Towing Tank. Given the very promising results of this new generation of LNG carriers, achieving besides the excellent propulsive properties also a higher payload target, the yard became more competitive and is expecting quite some orders for this particular ship type.

Hull Form Optimization Based on an NM+CFD Integrated Method for KCS

2020 ◽  
Vol 17 (10) ◽  
pp. 2050008
Author(s):  
Aiqin Miao ◽  
Decheng Wan
Keyword(s):  
Optimization Design ◽  
Model Building ◽  
Computational Cost ◽  
Hull Form ◽  
Integrated Method ◽  
Computational Fluid Dynamics Cfd ◽  
Hull Forms ◽  
Main Components ◽  
Hydrodynamic Optimization ◽  
High Computational Cost

This paper concerns development and illustration of a hydrodynamic optimization tool, OPTShip-SJTU, which contains four main components, i.e., hull form modifier, performance evaluator, surrogate model building, and optimizer module. It has been further developed by integrating a new method into the performance evaluator module, which combines the Neumann–Michell (NM) theory with computational fluid dynamics (CFD) technology, in order to reduce the high computational cost. To illustrate the practicality of further extension, OPTShip-SJTU was applied to optimize the hull form of KCS by simultaneously reducing drags at two speeds. A drag reduction was obtained by the optimal KCS of different hull forms. It turns out the presented method for ship optimization design is effective and reliable.

scholarly journals Research on aerodynamic characteristics of two-stage axial micro air turbine spindle for small parts machining

2020 ◽  
Vol 12 (12) ◽  
pp. 168781402098437
Author(s):  
Liu Jiang ◽  
Guo Zhiping ◽  
Miao Shujing ◽  
He Xiangxin ◽  
Zhu Xinyu
Keyword(s):  
High Speed ◽  
Aerodynamic Characteristics ◽  
Maximum Efficiency ◽  
Two Stage ◽  
Output Torque ◽  
Air Turbine ◽  
Solid Foundation ◽  
Computational Fluid Dynamics Cfd ◽  
Micro Machine ◽  
Small Parts

In order to meet the requirements of output torque, efficiency and compact shape of micro-spindles for small parts machining, a two-stage axial micro air turbine spindle with an axial inlet and outlet is proposed. Based on the k-ω turbulence model of SST, the flow field and operation characteristics of the two-stage axial micro air turbine spindle were studied using computational fluid dynamics (CFD) combined with an experimental study. We obtained the air turbine spindle under different working conditions of the loss and torque characteristics. When the inlet pressure was 300 KPa, the output speed of the two-stage turbine was 100,000 rpm, 9% higher than that of a single-stage turbine output torque. The total torque reached 6.39 N·mm, and the maximum efficiency of the turbine and the spindle were 42.2% and 32.3%, respectively. Through the research on the innovative structure of the two-stage axial micro air turbine spindle, the overall performance of the principle prototype has been significantly improved and the problems of insufficient output torque and low working efficiency in high-speed micro-machining can be solved practically, which laid a solid foundation for improving the machining efficiency of small parts and reducing the size of micro machine tool.

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 The Study of Religious Customs and Traditions of the Nanai in Russian Science (Pre-Revolutionary Context) and the Experience of Their Systematization in the Literary Ethnography of Venedikt Mart

2020 ◽  
pp. 137-147
Author(s):  
Kseniya A. Zemlyanskaya ◽  
Keyword(s):  
Material Culture ◽  
19Th Century ◽  
Russian Far East ◽  
Far East ◽  
Literary Form ◽  
Russian Science ◽  
Close Study ◽  
Wedding Ceremony ◽  
New Generation ◽  
The 19Th Century

In the 19th – early 20th centuries, the Nanai were one of the largest Tungus-Manchu peoples of the Russian Far East. A close study of their traditions and customs began in the middle of the 19th century, when numerous ethnographic expeditions of researchers (L.I. Shrenk, R.K. Maak, K.I. Maksimovich) were sent to the Amur. First of all, the researchers were interested in the material culture of the Nanai, the issues of religion were touched upon in the mainstream of ethnographic research. In the last quarter of the 19th century, the attention of researchers was directed to the description of Nanai rites of passage (D. Kropotkin, P.P. Shimkevich). Scientific expeditions of the early 20th century were aimed at describing the spiritual culture of the Nanai and its reflection in material culture (I.A. Lopatin, L.Ya. Sternberg). The description of the religious beliefs of the Nanai was recorded as a result of the missionary activities of Blagoveshchensk and Vladivostok dioceses. In 1932, the former Far East writer Venedikt Mart published the story “Dere – the Water Wedding”, where he accumulates and systematizes the accumulated knowledge about the Nanai people in literary form, introducing certain elements of fiction. Despite the fact that Venedikt Mart writes about the denial of religious customs and traditions by the new generation of Nanai, nevertheless, the story itself is, in fact, clearly fixed at its core by the content of the wedding ceremony

A Comparison of Several Strategies to Optimize a Ship’s Aft Body

2011 ◽  
Vol 27 (04) ◽  
pp. 202-211
Author(s):  
Auke van der Ploeg
Keyword(s):  
Viscous Flow ◽  
Scale Effects ◽  
Full Scale ◽  
Ship Hull ◽  
Hull Form ◽  
Wake Field ◽  
Hull Forms ◽  
Definition Of

This paper describes a procedure to optimize ship hull forms, based on double body viscous flow computations with PARNASSOS. A flexible and effective definition of parametric hull form variations is used, based on interpolation between basis hull forms. One of the object functions is an estimate of the required power. In this paper we will focus on how to improve this estimate, by using the B-series of propellers. Results of systematic variations applied to the VIRTUE tanker together with scale effects in the computed trends will be discussed. In addition, we will demonstrate how the techniques discussed in this paper can be used to design a model that has a wake field that strongly resembles the wake of a given containership ship at full scale.

The degree of using research systems and the satisfaction of Palestinian li-braries in the light of technological environment from the point of view of librarians and researchers

2020 ◽  
Vol 8 (3) ◽  
pp. 20-39
Author(s):  
Ibrahm Khader
Keyword(s):  
West Bank ◽  
Gaza Strip ◽  
Point Of View ◽  
Technological Environment ◽  
Relational Approach ◽  
Research Systems ◽  
Time Period ◽  
West Bank And Gaza ◽  
Search Index ◽  
New Generation

The present study aimed to identify the extent of using research systems that are the new generation for the library index, similar to the interface of the beneficiaries that allows access to all information, and satisfaction with it in Palestinian libraries in light of the technological environment from the viewpoint of librarians and researchers. It also aimed to identify whether there is any difference between the respondent’s occupational stress levels which can be attributed to their (Gender, major, library type, experience). The study’s population consists from all the all the Librarians and researchers in Palestine (West Bank and Gaza Strip). As for the sample, it consists from (300) From librarians and researchers in Palestine (West Bank and Gaza Strip). The researcher chose a descriptive, relational approach to its suitability with this study. The researcher Prepare an instrument a questionnaire for measuring the extent to which research systems are used and satisfied with the technological environment from the viewpoint of librarians and researchers. The results of the study showed that there are no statistically significant differences in the extent use of library systems and satisfaction with them in light of the technological environment from the viewpoint of librarians and researchers in what is attributed to the variable of gender and specialization, and the presence of statistically significant differences in the extent of use of library systems and satisfaction with it in the technological environment from The viewpoint of librarians and researchers regarding the variable type of library and years of experience. In the light of the aforementioned results, the researcher rec-efforts necessity design unified search index between the types of libraries in Palestine to unify the searches, which greatly reduces the time period spent.

Hydrodynamic Optimization of a Wedge Hull

2015 ◽  
Author(s):  
Lijue Wang ◽  
Fuxin Huang ◽  
Chi Yang ◽  
Raju Datla
Keyword(s):  
Hydrodynamic Performance ◽  
Surface Mesh ◽  
Nurbs Surface ◽  
Bottom Edge ◽  
Hull Form ◽  
Entrance Angle ◽  
Total Drag ◽  
Rounded Corner ◽  
Bulbous Bow ◽  
Hydrodynamic Optimization

A novel wedge-shaped hull form is optimized for reduced drag using a further developed practical hydrodynamic optimization tool. The hull features a sharp entrance angle, rectilinear sides, sharp bottom edges, a triangular waterplane and a linear aftward taper from a deep bow to a shallow transom. The optimization involves two modifications of the hull form, one is to smooth out the sharp bottom edge with a rounded corner and the other is to generate a bulbous bow. In order to perform the hydrodynamic optimization of the hull, a Non-Uniform Rational BSpline (NURBS)-based hull surface modification tool, a NURBS surface mesh generator, a surrogate model and an evolutionary optimization solver are developed and integrated into the practical hydrodynamic optimization tool. The hydrodynamic performances, i.e., the total drag and the flow field near the obtained hull bodies are assessed and compared with the original wedge hull using numerical simulations. Results showed that rounding the sharp edge of the wedge hull can reduce the total drag by alleviating the flow separations around the hull body. The wedge hull with rounded bottom edge and optimized bulbous bow can achieve larger drag reduction and the flow separations are almost eliminated. The total drag of the optimal hull is compared with an earlier-optimized wedge hull that has a different type of bulbous bow, whose hydrodynamic performance has been validated by model tests.

Entrepreneurial Orientation of Family Business

2019 ◽  
pp. 133-156
Author(s):  
Emel Faiz ◽  
Gamze Uludag
Keyword(s):  
Family Business ◽  
Entrepreneurial Orientation ◽  
Global Economy ◽  
Family Businesses ◽  
Rate Of Change ◽  
Point Of View ◽  
Added Value ◽  
Third Generation ◽  
Economic Development And Growth ◽  
New Generation

Family businesses are considered as an important source of economic development and growth in that they create added value by providing new products, processes and technologies. Family businesses, where family values and perspectives dominate, have begun to experience problems in adapting to such a structure in the global economy, where the rate of change has increased, and the competition is intense. In the process of restructuring, entrepreneurial orientation is vital for these businesses. From this point of view, the aim of this chapter is to define family business, to explain their characteristics and to show the two perspectives on the entrepreneurial orientation of family businesses. The concept of “family entrepreneurship” and “transgenerational entrepreneurship” is also mentioned in the chapter. In relation to what is told in the chapter, how a conservative structure has been opened to the market by its third generation, a family business in Turkey that is going through its third generation and the innovations brought about by the new generation compose the case study.

Smart Mesoporous Nanomaterials With Improved Therapeutic Applications

2018 ◽  
pp. 431-447 ◽  
Author(s):  
Sandhya Sanand ◽  
Anshika Tyagi ◽  
Sandeep Kumar ◽  
Gautam Kaul
Keyword(s):  
Drug Delivery ◽  
Mesoporous Silica Nanoparticles ◽  
Surface Modifications ◽  
Chemotherapeutic Agents ◽  
Point Of View ◽  
Site Specific ◽  
Comprehensive Review ◽  
Post Synthesis ◽  
New Generation ◽  
Toxic Drugs

Nanomaterials have revolutionized the drug delivery and therapeutic industry due to their unique physical characteristics, which render them extremely manipulative at nano-scale. One such category of nanomaterials is mesoporous silica nanoparticles. Due to their small size and rigid honeycomb-like structure, they are highly conducive for packaging of drugs, dyes, antibodies, etc. In addition, they show excellent biocompatibility. These new generation nanomaterials can be further functionalized by incorporating surface modifications, thus increasing their acceptability as carriers for drugs and molecules. In this chapter, a brief and comprehensive review covering various aspects of the recent advancements in synthesis of mesoporous nanomaterials and post-synthesis strategies for functionalization has been presented. Further, it also sheds light on how efficiently these smart nano-carriers are involved in transport and site-specific delivery of highly toxic drugs, like chemotherapeutic agents for cancer treatment, and their biocompatibility evaluation from a biosafety point of view.

scholarly journals Comparative Study on the Economic Efficiency of Rapeseed Culture in Conventional and Organic Systems

2018 ◽  
Vol 75 (1) ◽  
pp. 95
Author(s):  
Elena ȘURCĂ
Keyword(s):  
Economic Efficiency ◽  
Point Of View ◽  
Production Costs ◽  
Rate Of Return ◽  
Maximum Efficiency ◽  
Economic Point ◽  
Organic Systems ◽  
Use Of Resources ◽  
Revenue Structure ◽  
Crop System

From an economic point of view, efficiency implies the use of resources, of any kind, at maximum efficiency, or else the relation between effect and effort is over unit. In any kind of activity economic efficiency is the basis for its start. In the present paper, the level of economic efficiency for rape crops will be determined, according to two technological systems: conventional and organic. The revenue structure, and especially the expenditure, will be found in the income and expenditure budget of the culture. We will compare the value of production, production costs, but also yield or rate of return. In the continuation of the study, a set of indicators of economic efficiency will be calculated for each crop system, which will be subjected to a mirror analysis, to determine the feasibility of rapeseed crops as accurately as possible. Finally, the results will be presented, the profitability of the crop according to the system, the level of the profit and the recommendations regarding the future way of growing the rapeseed.

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