For over 25 years, the offshore industry has relied on the SNAME Guidelines for Wind Tunnel Testing for guidance in wind tunnel testing of MODUs and other offshore vessels for use in stability and drag calculations. In the intervening time, maximum drilling depths have increased three-fold, new vessel designs have flourished, environmental data has vastly improved, and numerical methods, particularly Computational Fluid Dynamics (CFD), have become well-established.
This paper addresses proposed modifications and improvements to the SNAME Guidelines for Wind Tunnel Testing, based on 32 years of tunnel testing of MODUs by Diamond Offshore in multiple wind tunnels, and the recent use of an improved portable model positioning system and balance which allows collection of data from different tunnels using the same model, balance and data acquisition system.
The paper will analyze wind tunnel types, balances and other force and moment techniques, wind profiles, pressure versus velocity measurement, Turbulent Intensity, Reynolds Number effects (including the effects of fine "details"), blockage effects and corrections, and tunnel leakage.
In addition, the paper will examine the role of CFD in MODU testing, especially the correlation of wind Tunnel and CFD test results, the economics of CFD in MODU testing, and the use of CFD to improve the accuracy of Wind Tunnel Testing.