Radial air gap

The mechanical clearance between rotating parts, e.g., fan and fan cover or the radial air gap between the stator and the rotor, should not be less than specified to prevent sparking. 

Radial Magnetic Pull. The radial magnetic pull of a motor or generator is the magnetic force on the rotor resulting from its radial (air gap) displacement from magnetic center. 

For e-rotating electrical machines, IEC 60079-7 and EN 50019 prescribe the minimum radial air gap (at standstill) according to ... 

Figure 6.56 Minimum radial air gap for asynchronous machines (at standstill) gmjn versus rotor diameter D, valid for 50 cps and r = 1.0.

As previously mentioned, auxiliary bearings are used to proteet eleetromeehanieal parts in ease of bearing overload or eleetronie failure. These auxiliary bearings are used for both radial and axial motion and are mounted on damping bands. The maximum air gap between the shaft and the auxiliary bearings is 0.25 mm (.010 in.) radial and 0.30 mm (.012 in.) axial, ineluding band defleetion of 0.07 mm (.003 in.). 

As the soil dries, roots often shrink in the radial direction, leading to the development of a root-soil air gap (Fig. 9-19). Hence less contact occurs between a root and the water adjacent to soil particles, leading to a hydraulic resistance at the root-soil interface. Such a resistance can decrease water movement from a root to a drying soil and thereby help prevent excessive water loss from plants during the initial phases of drought (Fig. 9-20). 

Water potentials and distances involved asa root-soil air gap is created by the radial shrinkage of a root during drought. 

The mutual coupling Xmd between the rotor and the stator is much influenced by the radial length of the air gap. 

The distribution of fillers across the membrane is vital to determine the morphology and performance of the composite hollow fibers. Jiang et al. [91] reported that (1) the shear rate within the spinneret, (2) the die swell at the outlet of the spinneret, and (3) the elongation draw at the air-gap region were the factors affecting the filler distribution in the mixed-matrix composite hollow fibers, whereas Xiao et al. [92] observed that a high elongation draw ratio can radially displace the fillers toward the bore and shell side of the composite hollow fibers. 

As can be seen in Fig. 29.2, the displacement sensor measures not only the variation of the gap size between the sensor head and the target surface but also the displacements due to error motion of a spindle s axis of rotation in radial direction and roundness errors of the target surface. These errors are simply compensated by subtracting the displacement signals measured while air cutting from the displacement signals measured while cutting. 

WSRC has developed a special code, FLOWTRAN-TF, based on the conservation of mass, energy, and momentum to account for two-phase flow, heat transfer effects, and cross-rib gap flows in assembly subchannels. The heat conduction models developed for FLOWTRAN-FI have been incorporated in FLOWTRAN-TF. Each subchannel coolant node has radially adjacent fuel surface temperature nodes to accommodate the heat transfer in the cell.. Rib fin effects are also handled in the same manner as they are in FLOWTRAN-FI. In order to initiate the computation, an air void fraction must be assigned to the computational cell above the fuel. This is done by assuming an air void volume in the first (top) axial cell as adjusted by an experimentally determined partitioning factor. Results from FLOWTRAN-TF have been shown to be relatively insensitive to the value assigned. Two-phase flow across the ribs is modeled by the application of an assumed partition factor based on values given in the literature. 

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