13.241. HSFLD241 - 2D Hydrostatic Fluid

Matrix or VectorShape Functions Integration Points
Stiffness MatrixSame as attached 2D solid element2 or 3
Load TypeDistribution
Fluid Mass Flow RateFluid mass flow rate at pressure node
Nodal TemperatureTemperature at the pressure node

HSFLD241 is used to model fluids that are fully enclosed by solids (containing vessels). The logic for HSFLD241 is very similar to that given for HSFLD242 - 3D Hydrostatic Fluid, with the differences noted below:

  1. The element thickness must be input on R command.

  2. If KEYOPT(3) = 0, the element behaves as 2D. The determination for plane stress or plane strain behavior is done based on the attached 2D solid element.

  3. If KEYOPT(3) = 1, the element behaves as axisymmetric.

  4. The set of orthonormal vectors on the fluid surface for defining fluid volume is given as:

    (13–329)

    where:

    n = outward normal vector (in X-Y plane) to the fluid surface enclosing the fluid volume
    t 1 = k = first tangent vector (normal to X-Y plane) to the fluid surface
    t 2 = second tangent vector (in X-Y plane) to the fluid surface

    Since the model stays in the X-Y plane, the variation of the first tangent vector is always zero. As a result, no geometric stiffness contributions are made from the rate of change of volume enclosed by the solid surface:

    (13–330)