Wind tunnel testing and computational fluid dynamics in FLNG and floating production system design
Johnathan Green A and Subajan Sivandran ABMT Fluid Mechanics.
The APPEA Journal 56(2) 613-613 https://doi.org/10.1071/AJ15119
Published: 2016
Abstract
Demonstrating how numerical modelling, such as computational fluid dynamics (CFD), can be used to validate results from detailed physical wind tunnel models of FLNG vessels and floating systems is the objective of this extended abstract.
3D rapid prototyping is used to build detailed physical wind tunnel models. This physical model (normally of an approximate scale of 1:200) is then placed in a wind tunnel facility to measure the time histories of the wind loads for a full range of wind directions and a range of drafts. CFD is then used to validate the wind tunnel modelling results.
Numerical modelling can also be used to analyse a number of different issues such as the impact of turbine exhaust dispersion, and turbulence on helicopter operations and resulting helideck availability.
This extended abstract discusses the importance of wind tunnel testing and numerical modelling during the design phase. The idea that numerical modelling does not replace pure theoretical or experimental results, but acts to complement them with gaining a greater overall picture, will be highlighted. Findings will be presented to discuss the advantages and disadvantages of both approaches, and highlight results such as wind shear and turbulence impacts being best calculated through wind tunnel testing.
The extended abstract demonstrates that, ideally during the design process, wind tunnel testing should be followed by numerical modelling to interpolate results.
Johnathan Green is the Line Group Manager for Numerical Modelling at BMT Fluid Mechanics Limited. In this role, he is responsible for managing various CFD projects, predominantly in the fields of oil and gas, marine, defence, environment, and power industries. Recent projects that Johnathan has managed for the oil and gas industry have provided a wide professional expertise of onshore and offshore safety case analysis using CFD (including natural and mechanical ventilation, gas dispersion and explosion), probabilistic risk assessment, conjugate heat transfer, and internal multiphase flow modelling (e.g. pipeline erosion and CO2 transport and dispersion). His work in the marine and defence Industries has mainly concerned hydrodynamic loading for hulls, submarines, pipelines and offshore floating facilities using CFD. He is an experienced user of several commercial CFD codes (e.g. ANSYS CFX, FLUENT, FLACS), meshing tools (e.g. ANSYS ICEM) and CAD packages (e.g. Rhino). Johnathan has a Bachelor of Science (Mathematics) (Hons) and holds a Master’s in Science (Computational Fluid Dynamics) from Cranfield University (UK). |
Subajan Sivandran is the head of oil and gas at BMT Fluid Mechanics Ltd and is responsible for managing strategy and business development globally for the oil and gas sector. He has worked extensively in gas related projects across 11 countries, carrying out risk and safety studies during the concept and detailed design phases of FLNG vessels. Suba has facilitated hazard identification, hazard and operability, and deck layout studies, carried out fire and explosion modelling and gas dispersion analyses, and delivered economic and reliability, availability and maintainability (RAM) studies on regasification installations for FSRUs and LNGRVs to optimise process configuration. Suba graduated from the University of Western Australia with a Bachelor of Engineering (Mechanical Engineering) and Bachelor of Science (Theoretical Physics and Applied Mathematics) and holds an MBA (Strategy) from HEC Paris. |
References
BMT Fluid Mechanics Ltd, 2001—Review of model testing requirements for FPSO’s, Health and Safety Executive, Her Majesty’s Stationery Office, Norwich, Offshore Technology Report 2000/123.Civil Aviation Authority, February 2013—Standards for Offshore Helicopter Landing Areas. Safety Regulation Group, The Stationery Office, Norwich, CAP 437.
Norsok Standard, 2001—Risk and emergency preparedness analysis, Rev. 2. Standards Norway, Strandveien Lysaker, Z-013.
Norsok Standard, 2004—Helicopter deck on offshore installations. Standards Norway, Strandveien Lysaker, C-004.
