Gravitational acceleration, relevance

If the answer to this question is affirmative, g is a relevant variable. The gravitational acceleration g can be effective solely in connection with the density as gravity gp. When inertial forces play a role, the density p has to be listed additionally. Thus, it follows that ... 

We interrupt the procedure to ask some important questions concerning (1) the determination of the characteristic geometric parameter, (2) the setting of all relevant material properties, and (3) the taking into account the gravitational acceleration. 

The relevance list must also include universal physical constants such as the universal gas constant, R, the speed of light in a vacuum, c, or even the acceleration of a gravitational field (on Earth the acceleration due to gravity, g), if these constants influence the process concerned. The fact that a relevant physical quantity is a constant can never be a reason not to include it in the relevance list By failing to consider the relevance of gravitational acceleration, the chemical engineer may find he has made a serious mistake ... 

The target quantity in this process is the temperature, T, of the liquid. We will include the cylinder diameter, d, as characteristic geometric parameter in the relevance list. The physical properties are the density, p, the viscosity, p, the heat capacity, Cp, the thermal conductivity, k, and the temperature coefficients of viscosity, y0, and of density, p0- The process parameters are the experimental time, t, gravitational acceleration, g (because of the density differences on account of the temperature field) and the two characteristic temperatures ... 

According to these premises, the relevance list must be formed with the following parameters Target quantity. kLa physical properties density p, viscosity i, diffusivity D and the coalescence parameters S of the liquid phase. Despite extensive research, coalescence phenomena have still not been clarified to such an extent as to permit explicit formulation of the coalescence parameters (see [22], section 4.10). Process parameters volume-related mixing power P/V, superficial velocity v of the gas and gravitational acceleration g. (The decision in favour of P/V and v instead of P/q and q/V was based on extensive research results obtained in the last three decades, see Section 10.4.1)... 

Table 8.1 Most relevant dimensionless numbers used in the analysis of droplet/(cold) sinface interactimis. p, p and o-j, stand for liquid specific mass, dynamic viscosity and surface tension, respectively and g is the gravitational acceleration ctmstant...

---