====== HEATX ======
3D heat exchange
===== Description =====
The element is defined by 4 or 6 nodes specified in NODES. \\ Currently, only the linear element is available. The element only works with thermal law [[laws:linadc|LINADC]]. \\
A classic element consists of 2 (or 3) pipe nodes as well as ground nodes to which they are connected. The heat exchange between the pipe and the ground is a function of the temperature difference between the fluid inside the pipe and the ground. \\
{{  :elements:heatx.png?600  |}}
\\
Type: 108 \\
Implemented by: B. Cerfontaine, 2015
==== Files ====
Prepro: HEATEXA.F \\
Lagamine: HEATEXB.F

===== Input file =====
^Title (A5)^^
|TITLE|"HEATX" in the first five columns|
^Control data (I5)^^
|NELEM|Number of elements|
^Definition of the elements (2I5/6I5)^^
|NINTE|Number of integration points (1, 2, or 3)|
|LMATE|Material law|
|NODES(6)|List of nodes (4 or 6), the meaning of the nodes varies depending on the value IBOUND in the law: \\ → IBOUND = 0 (normal) or IBOUND = 1 (free flow) \\  - Nodes 1 to 2 (linear case) or 1 to 3 (parabolic case): nodes of the volumic element to which the linear node is connected  \\ - Nodes 3 to 4 (linear case) or 4 to 6 (parabolic case): nodes of the pipe element, numbering direction defined in the positive rate of the flow \\ → IBOUND = 2 (loop condition) \\ - Nodes 1 to 2 (linear case) or 1 to 3 (parabolic case): Pipe IN nodes \\ - Nodes 3 to 4 (linear case) or 4 to 6 (parabolic case): Pipe OUT nodes|

===== Results =====
SIGMA: Conduction flow, advection, lateral storage