[NightWing]

Hello All
I was trying to run a case which involves bousinessq approximation(natural convection) and the pipe is exposed to heat flux. I was trying to apply the boundary condtion initially by using fixedGradient patch field type. Later while reading much forums and wiki's i decided to try groovyBC. I am little confused about setting up the patch parameters for groovyBC.

type groovyBC;
value uniform 298;
gradientExpression "gradT*time()";
fractionExpression "0";
variables "heatFlux=800;alpha=(0.6513*(1.0 + 3.933e-04* T));gradT=heatFlux/(alpha);";



i got this piece of info from the forums itse;f. I do understand that, groovyBC requires either a value expression or a value, then a graident expression, fraction expression followed by variables and timelines.

But can anyone give the proper explanation like some details of these entries in the groovyBC?? what does that value unfiorm 298 refer to? is it the reference temperature??

Similarly does anyone know any relation to study the variation of thermal conductivity of water (liquids) with temperature? similar to like for metals we use the relation k = ko(1+alpha*T)