... and valves, risk of fluid contamination, downtime due to regular flushing procedures, not easy to retrieve subsea, additional weight and space required by the HPU, etc. The main disadvantage of the available electric actuators is that they are not designed for such low torque levels. They normally offer...

...Introduction Electric actuators for wellhead and production trees An Electric Actuator (EA) system has a simpler overall design than a hydraulic actuator system ( Fig. 3 ) and has no requirement for complex HPU and associated size, weight, and cost. There is also no high-pressure hydraulic...

...; ISSN 1098-6189 A Coupled RANS-VOF and Actuator Disk Model for Floating Offshore Wind Turbines Edward J. Ransley, Scott A. Brown, Martyn R. Hann, Deborah M. Greaves School of Engineering, Computing and Mathematics, University of Plymouth Plymouth, U.K. ABSTRACT nonlinear phenomena associated...

... Abstract In the drive for remote operations, reducing operator costs and reducing emissions and CO2, digitalization of sensors and control systems is imperative. To date, valves on wellheads and trees have predominantly been controlled by hydraulic actuators that are not ideally suited...

... Aerospace Standard (NAS) oil purity level. Cost of operations can range from USD 30 000 per hour for smaller platforms to USD 200 000 or more for larger installations ( Pawlus et. al, 2016 ). Abstract PACT (Pressure control ACTuator) is a newly developed, all-electric wellhead- and production tree...

... source term coefficient upstream turbine drag coefficient turbine actuator line method downstream turbine social responsibility reservoir simulation ocean energy rotor tidal turbine sustainable development geometry method geometry simulation thrust coefficient experimental result...

... ABSTRACT The steering gear is the actuator of submarine course control system. For valve controlled hydraulic steering gear servo system in this paper, the composition of the hydraulic steering servo valve control system is introduced and the mathematical model is built through simulation...

... ABSTRACT Wake interaction normally occurs in all wind farms and impacts significantly the flow field and performance of downstream wind turbines. The present work aims to study the wind turbine wake interaction phenomenon through the CFD method using LES and actuator line model. The solver...

... uniform inflow condition eddy simulation sustainable development social responsibility drag coefficient churchfield sustainability meneveau turbine wind energy coefficient schmitz wake characteristic simulation inflow condition streamwise velocity actuator curve diameter...

... ABSTRACT The actuator line method (ALM) introduces an actuator-line to represent a wind turbine by adding a body force term in the momentum equation. As ALM simplifies the process of mesh refinement and moving mesh, it can get much higher efficiency for wind turbine wake simulation...

... Abstract Although subsea production is already a mature technology, a high engineering effort is currently needed to "industrialize" the applied systems for cost optimization. The drive system applied for the actuation of subsea valves in trees and manifolds reflects exactly this challenge: how...

... using actuator line model and CFD method, and the RANS equation with k-ω SST turbulence model was solved in the simulations conducted in the OpenFOAM. From the study, it is concluded that the inter-turbine spacing has significant effects on the aerodynamic power and wake characteristics. The aerodynamic...

... Abstract Computations of the blade loading and the local flow field around the Model Rotor Experiments In Controlled Conditions (MEXICO) rotor are presented using an actuator line method, implemented within the open source code OpenFOAM. The nacelle and near wake mesh refinement are shown...

... Abstract A modified locally optimal and globally inverse optimal controller for dynamic positioning (DP) is constructed by using backstepping methodology and optimal control method. The motivation is the existence of undesired signal sent to the actuators which can result in bad behavior in DP...

... is being on the realistic depiction of the far wake rather than on the actual flow dynamics at the rotor blades. For the purpose of assessing and analyzing the turbine's performance in a tenable computing time, an Actuator Disc approach has been implemented into a CFD simulation model in ANSYS CFX...

... ABSTRACT Hydrogen absorbing alloys have been studied to examine their effectiveness for storage of hydrogen. The Metal Hydride actuator (MH actuator) is being developed as a method for directly obtaining a mechanical force using hydrogen pressure generated by a temperature difference applied...

... ABSTRACT Air Power & Hydraulics perceived a need for an improved pan and tilt actuator mechanism which, in conjunction with a camera, could be fitted to Remotely Operated Vehicles (ROVs) and used to assess the condition of underwater installations. The company decided to develop...

... System and the diverless intervention method. The analysis of the conception of existent manifolds indicated that some simplification could be made without loss of reliability or functionality. This paper describes the development of the MAC Manifold, a monogram in Portuguese of Shared Actuator Manifold...

... Abstract This paper reviews the continuing development of gate valve and actuator technology for subsea completions extending into ultra deep water. The basic technical challenges inherent to subsea valve actuators are reviewed, along with the various factors which affect the design...