Leading edge

Inspection of joints between the shells on the leading edge. 

In set-up 2 the leading edge can be scanned by means of a special designed Y-module that allow the probe to follow the complex geometry of the leading edge from the root to the tip of the rotor blade. In figure 4 set-up 2 is illustrated. 

When the scanning of the adhesive bonded joint between the shells on the leading edge is complete, the rotor blade is rotated 180° and another special designed Y-module is applied for inspection of the trailing edge of the rotor blade in set-up 3, illustrated on figure 5. 

Fig. 4 Y-module positioned for set-up 2, for inspection of bonded areas on the leading edge.

Figure 4.13 Schematic illustration of the leading edge of a lathlike crystal within a spherulite.

The practice of employing reusable thermal protection systems for reentry is becoming more common. These are essentially ablative materials exposed to environments where veryHtde ablation actually occurs. Examples iuclude the space shuttle tiles and leading edges, exhaust no22le flaps for advanced engines, and the proposed stmctural surface skin for the National Aerospace plane. 

Other forms of carbon-carbon composites have been or are being developed for space shutde leading edges, nuclear fuel containers for sateUites, aircraft engine adjustable exhaust nozzles, and the main stmcture for the proposed National Aerospace plane (34). For reusable appHcations, a siHcon carbide [409-21 -2] based coating is added to retard oxidation (35,36), with a boron [7440-42-8] h Lsed sublayer to seal any cracks that may form in the coating. 

Water Treatment Chemicals and Equipment Outlook for the 1990 s, Leading Edge Reports, Cleveland Heights, Ohio, 1991, pp. 113—128. 

Eor drilling, the discharge action occurs at the leading edge of the tool, whereas ECM takes place on the side walls between the tool and the workpiece. The combined spark erosion and ECM action yields fast rates of metal removal. Because ECM is stiU possible, any metallurgical damage to the components caused by the sparking action can be removed by a short period (eg, 15 s) of ECM after the main ECAM action. Currents of 250 A at 30 V are typically used in the process. 

The theory has beea exteaded to evaluate sheet breakup (19). This model (19) assumes that the fastest growing wave detaches at the leading edge ia the form of a ribboa with a width of a half-waveleagth. The ribboa ioimediately coatracts iato multiple ligaments, which subsequeatly reshape themselves iato spherical droplets. The characteristic dimension of the ligament, Dy is as foUows, where / is the sheet thickness at the breakup locatioa. 

However, the transition Reynolds number depends on free-stream turbulence and may range from 3 X 10 to 3 X lO ". The laminar boundary layer thickness 8 is a function of distance from the leading edge ... 

Here the second term accounts for the laminar leading edge of the boundaiy layer and assumes that the critical Reynolds number is 500,000. 

Impeller Clearance Adjustment. AU pumps shall have provisions for adjustment of axial clearance between the leading edge of the impeller and casing. This adjustment shall he made by a precision microdial adjustment at the outboard hearing housing, which moves the impeller forward toward the suction wall of the casing. 

When the adsorption equihbrium is nonlinear, skewed peaks are obtained, even when N is large. For a constant separation-factor isotherm with R < 1 (favorable), the leading edge of the chromatographic peak is steeper than the trailing edge. Wmen R > 1 (unfavorable), the opposite is true. 

Thus, the effluent concentration becomes zero at Ti Tp = 1/R. The position of the leading edge (a shock front ) is determined from Eq. (16-132) ... 

With the pump di.sa.ssemblcd in the shop, with open impellers, the damage is seen on the leading edge of the impeller blades toward the eye of the impeller, and on the blade tips toward the impeller s OD. With enclosed impellers, the damage reveals itself on the wear bands between the impeller and the volute casing. See the illustration (Figure 3-2). 

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