we spent a fortune in offshore vessel days installing helical strakes onto a pipeline riser. These were literally helically wound to disrupt the flow of seawater around it at a approx speed of 1-10m/s, against a flowline that could be anything from 6"-12" OD. To make it more complex the current...
I understand mine perfectly. But the strake technology is more applicable to aerospace. Hence why I am asking.
The only strakes we get subsea are clamp on. I'm looking to put it into the pipeline coating but have never gone into depth analysing strake design. Hence the question and EXAMPLE golf...
DudePipe,
DNV-OS-F101 Section O400 'Submarine Pipeline Design Code' stipulates equations for calculating the exact allowable ID, OD, ovality....
(to name a few.)
for the purposes of pigging, gauging or brushing operations.
Dmin,tot = Dmin(1-f0/2)-2tmax-2hbead
it incorporates weld bead and...
Robb4,
i work within subsea pipe lay industry for a leading contractor.
A Bundled pipeline solution is definitely the most cost effective. Use sacrificial anodes on the main line only and attach to piggyback line with spot welds (or other) at predetermined spacing to provide continuity. The...
mineweld, your question is too vague.
when calculating weld size, it depends on stick/parent material used, throat size and expected loading.
Last time i designed a weld i used "design of weldments handbook" to give me an allowable stress per mm/2. Then manipulated as required to determine...
hello fellow like minded engineers!
I am seeking to transfer strake technology from aerospace to a subsea environment as a method of mitigating Vortex induced vibrations. A problem i am sure the aerospace industry must be familiar with. The effect of fluid flow induced vibration has on a wing...
chicopee is talking about general viusual inspection which in the Uk is to be conducted every 6 months as part of LOLER regulation. (Lifting Ooperations and Lifting Equipment Regualtions).
Wire ropes are a complex class of their own. Visual inspection is not adequate. (Although i believe it...
Hydrogen can be created chemically as a result of seawater and electrical current.
The small airpockets that are created then expand with any heat or contract with cooling resulting in degraded lifespan of said elec. connector.
its a chemical process and combined with water pressure/heat...
dw1982
the time it takes any FEA program to solve a problem is linked to
(a) the increment step size
(b) the logging rate
the larger these two are, the shorter the analysis time. But rule of thumb is logging should be at half that of increment. This will avoid spikes in yoru output data.
Hi Sj
Why not just use Orcaflex to analyse this problem? I use this program daily for pipelay analysis. It also allows you to change the seabed parameters although i will admit it does not model the interaction of pipe/seabed well.
I am new at Abaqus but have an upcoming tutorial at work soon...
