Specific heat capacity at constant volume

The specific heat capacity of a material on a per mass basis is $c = \delta C/\delta m$. with $C$ being the heat capacity of a body made of the material and $m$ being the mass of the body. It is the amount of heat required to change the temperature of a mass unit of a substance by one degree. When calculating mass and volume flow in a water heating systems at higher temperature, the specific heat should be corrected.

The sources are:

Symbol
$c_{v_{w}}$
Unit
J/kg.K
Formulae
$0.00032368 \theta_{w}^{3} + 0.047344 \theta_{w}^{2} - 2.20064 \theta_{w} + 4217.4$
Related
$\theta_{w}$
Water temperature [$^{\circ}$C]
Choices
Liquid0.01$^{\circ}$C10$^{\circ}$C20$^{\circ}$C25$^{\circ}$C30$^{\circ}$C
Fresh water4217.44191.04157.04137.94117.5