Lift, force

The drag force is exerted in a direction parallel to the fluid velocity. Equation (6-227) defines the drag coefficient. For some sohd bodies, such as aerofoils, a hft force component perpendicular to the liquid velocity is also exerted. For free-falling particles, hft forces are generally not important. However, even spherical particles experience lift forces in shear flows near solid surfaces. 

L = lift force D = drag force Cl = lift coefficient Cd = drag coefficient A = surface area p = fluid density V = fluid velocity... 

The simplest relationship for calculating fragment range neglects drag and lift forces. Vertical and horizontal range, and z, then depend upon initial velocity and initial trajectory angle Oj ... 

Auftriebskraftt /. buoyant (or buoying) force, lifting force. 

The theory of bulk liquid turbulent structure control in combination with the transverse lift force (Drew et al., 1978 Lahey, 1988)... 

The term capillary action describes the upward movement of a fluid as a result of surface tension through pore spaces. The fluid can rise until the lifting forces are balanced by gravitational pull (see Figure 3.28). The rise of fluid in a small tube above the water table surface, as previously discussed in Chapter 3, can be described using Equation 3.13. Lifting of fluids above the water table is a true negative pressure compared with atmospheric pressure (also described as soil suction). In soil situa-... 

Scale-up of spin-filters has been often studied in the recent years, and simple scale-up procedures have been proposed by Yabannavar et al. [81] and Deo et al. [13]. Yabannavar et al. [81] suggested a procedure based on keeping the ratio of permeation drag to lift force constant for the different production scales, in... 

Yabannavar et al. [81] proposed a proportionality relationship valid for spin-filters based on an analogy to Eq. (15). They defined the Reynolds number based on the tangential velocity at the screen surface. Since in spin-filters the permeation velocity, or perfusion flux, is given by Eq. (16), and it can be assumed that the screen porosity e will be maintained constant throughout the scale-up process, it is possible to write a proportionaHty relationship for the ratio from drag to lift force in spin-filters as given by Eq. (17). 

Test questions about levers will typically require a bit of math (multiplication and division) to solve the problem. There is one simple concept that you must understand to solve lever problems The product of the weight to be lifted times the distance from the weight to the pivot point must be equal to the product of the lifting force times the distance from the force to the pivot point. Stated as an equation w x dj =/x 2-... 

For example. Bill has a 15-foot long lever, and he wants to lift a 100-pound box. If he locates the pivot point 5 feet from the box, leaving 10 feet between the pivot point and the other end of the lever where he will apply the lifting force, how hard must he press on the lever to lift the box ... 

The lifting force of the vapor, is proportional to the momentum of the vapor. 

The aerodynamic entrainment model is based on the comparison between the distributions of forces holding the particles on the bed and of the lift force exerted on the particles by the flow. The expression of the take-off criterion is given for each size range by ... 

Fig. 3. Integration of the effect of the pavement by diminishing by graduated steps the lift force exerted on a particle.

For each size range, the value of the lift force is then decreased as soon as all the particles of a layer have taken-ofif. 

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