7.3 Convective / Radiative Surfaces

CONVECTIVE_SURFACE

CONVECTIVE_SURFACE number_of_loads = nload , etc...

m , hx(m) , Teta(m) , n(m) ,
T₀(m) < for m = 1 , number_of_loads >

< connectivity data > (see Chapter 11)

Note Variable Name Type Default Description

Load_case_number integer [*] Load case number (only required
in Restart mode)

Number_of_loads integer [1] Number of Surface Loads: Nload 1

Element_shape list [*] Element shape

four_node_quad

eight_node_quad

three_node_tri

six_node_tri

two_node_line

three_node_line

Geometry_type list [*] Geometry Option

one_dimensional

plane

axisymmetric

three_dimensional

Finite_deformation list [off] Finite Deformation Option

on / off If on: Use Updated (Deformed)

Geometry

File_name string [none] File name (optional). Name must

be enclosed in quotation marks.

7.3.1 Surface Loads Data

Note Variable Default Description

M [0] Load set number 1 and Nload

(1) h_x(M) [0.0] Heat transfer coefficient

Teta(M) [0.0] Surrounding (absolute) temperature

(2) n(M) [0.0] Power exponent

T₀(M) [273.15] Reference temperature

Notes/

(1) The heat flux (per unit area) generated by each surface is computed as:

q = h_x ( Tⁿ - Tetaⁿ )

where T = ( + T₀) = (absolute) temperature of solid medium. For radiative boundaries, the heat transfer coefficient hx is defined as:

where:

= Stefan-Boltzman constant = 5.6697 10^-8 Watt / m² / (°K)⁴

= surface emissivity

(2) For Convective boundaries: n = 1; for Radiative boundaries: n = 4.

7.3.2 Surface Nodal Connectivity Data

Consult Chapter 11 for details. For 1D problems NEN = 1, for 2D problems NEN = 2 or 3, and for 3D problems NEN = 3, 4, 6 or 8.