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Measurement
Published in Carl Hopkins, Sound Insulation, 2020
Raindrops with diameters larger than 1mm can be classed as rain whereas smaller drops are generally referred to as drizzle. Raindrop diameter depends upon the rainfall rate, temperature, and humidity. In temperate climates there is rarely any need to consider drop diameters larger than 5 to 6mm; larger drops than this will break up into smaller drops on their way down. Terminal velocities are shown in Fig. 3.51 and generally increase with increasing raindrop diameter. The terminal velocity tends towards a plateau for large drops because the aerodynamic drag force increases due to the distorted drop shape.
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Published in Mohammad H. Sadraey, Aircraft Performance, 2017
In this section, the numerical analysis of a free fall is presented, where an object is falling under the force of its weight, while the drag is acting in the opposite direction. Whenever the drag is equal to the weight, the velocity is referred to as the terminal velocity. Theory behind drag and governing equations for a free fall are presented in Chapters 1 through 3, so they are not repeated here. Figure 10.3 illustrates the active forces in a free fall.
Separation
Published in B. K. Bala, Agro-Product Processing Technology, 2020
From Equation 12.39, it is observed that the terminal velocity is directly related to the square of the particle diameter. In addition, the terminal velocity is dependent on the density of the particle and properties of the fluid. Equation 12.39 is the most common form of Stokes’ law and should be applied only for streamline flow and spherical particles. When the particle is not spherical, shape factor is used.
A novel dry gravity separation method for cleaner production of fine sized iron ore concentrate
Published in Canadian Metallurgical Quarterly, 2021
Ranjeet Kumar Singh, Ganesh Chalavadi, Ambesh Gupta, Achintya Kumar Das
The principle of separation in the dry gravity separator exploits the terminal velocity difference between a high-density particle (a particle with high iron content) and a low-density particle (a particle with low iron content). Terminal velocity of the particle is defined as the constant velocity with which particle leaves the system due to drag force, and buoyancy force of fluid (air in this case) overcomes the particle weight.