Recent Developments in Ride Control

2015 ◽  
Author(s):  
Alan J. Haywood ◽  
Benton H. Schaub ◽  
Chris M. Pappas

The use of ride control systems on high speed vessels has become the norm within many industries, producing better seakeeping that in turn provides a more comfortable and operationally effective vessel. Commercial ferry designers have been at the forefront of adoption of new technologies notably with early adoption of T-foils and interceptors. These devices have been taken up by others, for example offshore crew boats and frontline naval warships. The range of vessel types has also expanded with more industries adopting different hull designs including catamarans and trimarans. Ride control systems have developed alongside innovative designers producing for example combined lifting foil and ride control systems, lifting T-foil systems, retractable T-foils. This paper will review the different ride control devices including fins, trim tabs, interceptors, T-foils (including retractable T-foils) and lifting foils. As well as technical aspects, the discussion will consider costs, ease of installation, operational and maintenance requirements and material choice. Extensive examples from a wide range of industries will be presented. By the end of the talk, delegates will have a broad understanding of the options available to them in improving the seakeeping of their vessels.

2021 ◽  
Vol 163 (A1) ◽  
pp. 29-40
Author(s):  
M R Davis

Wave slam produces dynamic loads on the centre bow of wave piercing catamarans that are related to the relative vertical motion of the bow to the encountered wave surface. Rapid slam forces arise when the arch sections between centre bow and main hulls fill with rising water. In this paper time domain solutions for high speed ship motion in waves, including the action of active motion controls, are used to compute the slam forces. Slamming occurs at specific immersions of the bow whilst the peak slam force is characterised by the maximum relative vertical velocity of the bow during bow entry. Vertical motions of bow and encountered wave are in antiphase at encounter frequencies where slamming is most severe. The range of encounter frequencies where slamming occurs increases with wave height. Wave slam loads reduce ship motions, the heave motion being most reduced. Deployment of a fixed, inactive T-foil can reduce slamming loads by up to 65 %. With active controls peak slamming loads on the bow can be reduced by up to 73% and 79% in 4 m and 3 m seas, local control feedback being marginally the most effective mode of control for reduction of slamming.


Author(s):  
J AlaviMehr ◽  
M R Davis ◽  
J Lavroff ◽  
D S Holloway ◽  
G A Thomas

Ride control systems on high-seed vessels are an important design features for improving passenger comfort and reducing motion sickness and dynamic structural loads. To investigate the performance of ride control systems a 2.5m catamaran model based on the 112m INCAT catamaran was tested with an active centre bow mounted T-Foil and two active stern mounted trim tabs. The model was set-up for towing tank tests in calm water to measure the motions response to ride control step inputs. Heave and pitch response were measured when the model was excited by deflections of the T-Foil and the stern tab separately. Appropriate combinations of the control surface deflections were then determined to produce pure heave and pure pitch response. This forms the basis for setting the gains of the ride control system to implement different control algorithms in terms of the heave and pitch motions in encountered waves. A two degree of freedom rigid body analysis was undertaken to theoretically evaluate the experimental results and showed close agreement with the tank test responses. This work gives an insight into the motions control response and forms the basis for future investigations of optimal control algorithms.


Author(s):  
Preeti Rana ◽  
Durgesh Pandey

In recent years we have seen a number of changes in banking sector of India. Main objective of banks is to create more value for customers; that is why most of the banks have begun to take an innovative approach for this purpose. In the world of banking and finance, nothing stands still. Now a day's banking activities is not limited to deposit and lending money to customers Apart from traditional business, banks provide a wide range of services to satisfy the needs of all types of customers whether it is financial or non-financial needs from the smallest account holder to the largest company and in some cases of non-customers. As a result of recent developments, the entire banking industry has restructured and new technologies are also introduced to make it competitive. Revolution of Information Technology has made it possible to provide ease and flexibility in operations to customers thus making life simpler and easier so bank can provide a variety of products and services to the customers. The E-Banking process has changed the way of working of banks across the world. In the chapter, the author reviews the literature on “The issues and challenges of e-banking service operation” what is the perception of people towards E-Banking in different developing countries?” As E-Banking is an emerging concept in the field of commerce and banking. This paper furnishes the study of E-banking in developing countries through an analysis of content & existing literature that focused on developing countries. The main purpose of the study is to present the current level of research on E-banking in developing countries. Electronic banking (e-banking) is the new technology in banking environment that allows the bank customers to do banking activities at any time and from any place.


2019 ◽  
Vol 178 ◽  
pp. 410-422 ◽  
Author(s):  
Javad AlaviMehr ◽  
Jason Lavroff ◽  
Michael R. Davis ◽  
Damien S. Holloway ◽  
Giles A. Thomas

Author(s):  
Peter M. Pachlhofer ◽  
Joseph W. Panek ◽  
Dennis J. Dicki ◽  
Barry R. Piendl ◽  
Paul J. Lizanich ◽  
...  

The Propulsion Systems Laboratory at the National Aeronautics and Space Administration (NASA) Glenn Research Center is one of the premier U.S. facilities for research on advanced aeropropulsion systems. The facility can simulate a wide range of altitude and Mach number conditions while supplying the aeropropulsion system with all the support services necessary to operate at those conditions. Test data are recorded on a combination of steady-state and high-speed data-acquisition systems. Recently a number of upgrades were made to the facility to meet demanding new requirements for the latest aeropropulsion concepts and to improve operational efficiency. Improvements were made to data-acquisition systems, facility and engine-control systems, test-condition simulation systems, video capture and display capabilities, and personnel training procedures. This paper discusses the facility’s capabilities, recent upgrades, and planned future improvements.


2014 ◽  
Vol 65 (6) ◽  
pp. 508 ◽  
Author(s):  
J. Schellberg ◽  
E. Verbruggen

Grassland scientists and farmers are increasingly faced with emerging new technologies and information systems that have been primarily developed in engineering sciences, in particular, precision agriculture, remote sensing, geographic information and biotechnology. Judgment upon whether the implementation of any of these technologies may be beneficial in economic and ecological respects is challenging, especially to those who have to make on-farm decisions. New technologies have been applied on grassland only partially and with some delay compared with arable land. However, as we will show here, there is scope for successful implementation of new technologies in various climatic regions and for a wide range of applications. The paper presents the most important recent developments of new technologies in agriculture that have scope for application in grasslands. It defines the relevant terms and processes, provides examples of successful implementation, and discusses future directions and research needs.


Electronics ◽  
2021 ◽  
Vol 10 (22) ◽  
pp. 2863
Author(s):  
Yujie Guo ◽  
Fang Yuan ◽  
Yukuan Chang ◽  
Yuxia Kou ◽  
Xu Zhang

This article proposes a high-frequency, area-efficient high-side bootstrap circuit with threshold-based digital control (TBDC) that is directly charged by BUS voltage (DCBV). In the circuit, the voltage of the bootstrap is directly obtained from the BUS voltage instead of the on-chip low dropout regulator (LDO), which is more suitable for a high operating frequency. An area-efficient threshold-based digital control structure is used to detect the bootstrap voltage, thereby effectively preventing bootstrap under-voltage or over-voltage that may result in insufficient driving capability, increased loss, or breakdown of the power device. The design and implementation of the circuit are based on CSMC 0.25 µm 60 V BCD technology, with an overall chip area of 1.4 × 1.3 mm2, of which the bootstrap area is 0.149 mm2 and the figure-of-merit (FOM) is 0.074. The experimental results suggest that the bootstrap circuit can normally operate at 5 MHz with a maximum buck converter efficiency of 83.6%. This work plays a vital role in promoting the development of a wide range of new products and new technologies, such as integrated power supplies, new energy vehicles, and data storage centers.


Author(s):  
N. C. Balnes ◽  
N. Bressloff

This paper describes studies of simple gas turbine engines integrated with electrical transmission components. Recent developments in high-speed lightweight electrical machines and compact power electronics have enabled alternators and motors to be produced which can be coupled directly to the shaft of a gas turbine without an intermediate gearbox. For applications which require a wide range of power outputs, a single-shaft gas turbine with a high speed alternator can be run at constant speed while varying the current drawn from the alternator. This combines the flexibility of operation of a separate power turbine with the simplicity of a single-shaft engine. With this arrangement, in traction use high torques are obtained at low speed, while near-constant engine efficiency is sustained to about 50% of the design power. In the differential engine, the mechanical linkage between the compressor and the turbine is replaced with an electrical linkage. The turbine drives an alternator, and part of the alternator power is taken by a high-speed motor to drive the compressor. The excess alternator power forms the output of the engine. The compressor and turbine are now able to run at different speeds, and their operating points can be separately optimised at different engine conditions. For such an engine, studies show that high efficiency can be maintained to low power levels.


Sports ◽  
2019 ◽  
Vol 7 (5) ◽  
pp. 98 ◽  
Author(s):  
Stephen W. West ◽  
Sean Williams ◽  
Simon P. T. Kemp ◽  
Matthew J. Cross ◽  
Keith A. Stokes

In an effort to combat growing demands on players, athlete monitoring has become a central component of professional sport. Despite the introduction of new technologies for athlete monitoring, little is understood about the practices employed in professional rugby clubs. A questionnaire was circulated amongst conditioning staff across the 12 Premiership rugby clubs to capture the methods used, relative importance, perceived effectiveness and barriers to the use of multiple different athlete monitoring measurements. Previous injury, Global Positioning System (GPS) metrics, collision counts and age were deemed the most important risk factors for managing future injury risk. A wide range of GPS metrics are collected across clubs with high-speed running (12/12 clubs), distance in speed zones (12/12 clubs) and total distance (11/12 clubs) the most commonly used. Of the metrics collected, high-speed running was deemed the most important for managing future injury risk (5/12 clubs); however, there was considerable variation between clubs as to the exact definition of high-speed running, with both absolute and relative measures utilised. While the use of such monitoring tools is undertaken to improve athlete welfare by minimising injury risk, this study demonstrates the significant heterogeneity of systems and methods used by clubs for GPS capture. This study therefore questions whether more needs to be done to align practices within the sport to improve athlete welfare.


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