Coefficient of volumetric expansion

Djj. The Grashof number Nq, = Dj pgpAto/p" were is equivalent diameter, g is acceleration due to gravity, p is coefficient of volumetric expansion, p is viscosity, p is density, and Atg is the difference between the temperature at the wall and that in the bulk fluid. Nq, must be calculated from fluid properties at the bulk temperature. 

P = coefficient of volumetric expansion Atfj = the difference between the temperature at the wall and that in the bulk fluid... 

The data on the volume properties of PMS liquids (i.e. coefficient of volumetric expansion, relative volume variation, coefficient of isothermal compressibility) are essential for the performance characteristics of oli-godimethylsiloxanes in hydraulic systems, hydraulic shocks and dampers they allow one to determine the working characteristics of these systems with some brands of PMS liquids at different temperatures and pressures. 

Branched oligomethylsiloxanes PMS-lb - PMS-3b are soluble in aromatic hydrocarbons, do not corrode construction materials and alloys, are nontoxic. If heated above 200 °C, they form moderately toxic volatile substances, which excite the nervous system and cause conjunctivitis and inflammation of upper airways. The temperature of self-inflammation of these liquids exceeds 340 °C. Their coefficient of volumetric expansion ranges from 0.0013 to 0.0009 cm3/grad. 

Herein p is the thermal coefficient of volumetric expansion of the fluid. 

A polymer s dimensional changes are quantified using expansivity or coefficient of (volumetric) expansion ((3 or a ) and the coefficient of linear thermal expansion (a or CLTE). Since volumetric expansion and shrinkage are typically determined from pvT data, they are relatively isotropic. Thus, in theory, linear and volumetric expansion are related by... 

The foregoing is based on the pointwise expression for the coefficient of volumetric expansion at constant temperature, customarily denoted by P ... 

For an ideal gas, if the coefficient of volumetric expansion P is again denoted as... 

For the record, a coefficient of volumetric expansion at constant pressure may be portrayed in the partial derivative form ... 

Since P is customarily used to denote both the coefficient of pressure expansion for a gas and the coefficient of volumetric expansion for a liquid, here the latter usage is replaced by the symbol c. 

Coefficient of volumetric expansion (high) affects thermal pumping capacity and, where primary coolant is also the fuel, reactor reactivity. 

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