FIG. 1 STRESS AMPLITUDE HISTORY
0 4 8 12 16 20 24
SINGLE-DECK FLOATING ROOF FIG. 2
Automatic bleeder vent
Roof supports Roof support
Liquid surface level
ring Tank shell
82 Oil & Gas Journal | Apr. 3, 2017
damage it. 2 Strain and temperature were measured on an
actual floating roof via visual fiber gauges. Thermal stress on
the floating roof turned out to be too small to cause initial
cracking (Fig. 1). Temperature fluctuations over the course
of a day, however, could affect crack propagation.
Other researchers concentrated on heat transfer inside
storage tanks. 3 Some developed an estimate model for the
2D temperature field of an enormous floating roof tank and
inspected solar radiation’s effect on liquid temperature as
related to rooftop thickness. Another study examined the
intentional heating of a vertical storage tank using ANSYS
Fluent and deliberated the heating equipment’s influence by
The investigated tank (Fig. 2) had a 40-m diameter, was 23
m tall, and held 700-kg/cu m density oil. The external single-deck floating roof’s outside diameter measured 39. 6 m.
The single-deck floating roof consisted of SA283 Grade C
steel with a 7,850 kg/cu m density.
This study used Solidworks flow-simulation software. The CFD software contains turbulence models,
Navier-Stokes equations, and models
for physical phenomena. Simulating
flow via CFD can accelerate the design
stage and improve the reliability and
predictability of operations.
Solidworks flow simulation is
founded on two principles:
• Direct use of 3D CAD as the geometry information source.
• Grouping of full 3D CFD modelling with simpler engineering techniques in cases when the mesh resolution is insufficient for full 3D
The software uses multiple technol-
ogies to function within the CAD system:
• CAD data management.
• Mesh generator.
• Engineering modelling.
• CFD solvers.
• Results processing.
The study used discrete ordinates. The 4π directional domain within the computational domain at any position is
discretized into the definite number of equivalent solid angles. Equation 1 calculates radiation. 4
Radiation-absorptive solids absorb and produce thermal
radiation based on the coefficient of the identified solid material’s absorption. While scattering is not taken into consideration, opaque solids’ surfaces absorb thermal radiation
based on coefficients of their specific emissivity. The rest of
a radiation incident is imitated diffusively or specularly, depending on their coefficient of specified specularity.
Radiation normally is refracted according to the specified
indices of refraction of the solid and adjacent medium: a trans-