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Shaft Engines
Published in Ahmed F. El-Sayed, Aircraft Propulsion and Gas Turbine Engines, 2017
A Wankel engine is considered to be the optimum powerplant for a light aircraft, as it is light, compact, almost vibrationless, and has a high power-to-weight ratio. Further aviation benefits of a Wankel engine include thatThe rotors cannot seize, since rotor casings expand more than rotorsIt is not susceptible to “shock-cooling” during descentIt does not require an enriched mixture for cooling at high powerThe first Wankel rotary engine aircraft was the experimental Lockheed Q-Star civilian version of the United States Army’s reconnaissance QT-2 in 1967. It was subsequently installed in a variety of aircrafts including the Diamond DA20, a general aviation aircraft designed for flight training. Moreover, Wankel engines, due to their compact size and quiet operation, are used in drones or UAVs; an example of this, the AAI RQ-7 Shadow is shown in Figure 6.4.
Durability of structural adhesive joints for facade applications exposed to the extended cataplasm test
Published in The Journal of Adhesion, 2019
K. V. Machalická, M. Vokáč, M. Kostelecká, M. Eliášová
As it has been mentioned above, building facade joints have to transfer loads reliably and withstand relatively high environmental impacts (changes in temperatures, high temperatures and freezing temperatures, high RH, and, according to the geometry, water flooding and UV radiation), and, in addition, facades are required to have a longer service lifetime than the automotive or aviation structures. For this reason, immersion in water and dry heat conditions were added to the cataplasm test, which is described in ISO 9142, Procedure E2. One batch of specimens, containing both adhesives and all types of substrates, was exposed to the Extended Cataplasm Test based on ISO 9142, Procedure E2. The whole laboratory ageing procedure, Extended Cataplasm Test, consisted of six steps: 7 days of conditioning at 23°C and 50% RH,7 days of immersion in demineralized water at a temperature of 20°C, followed by 2 hr of conditioning in room conditions (23°C, 50% RH),1 day in a temperature chamber heated to 80°C, followed by 2 hr of conditioning in room conditions (23°C, 50% RH),7 days at 70 ± 2°C and 100% RH,freezing conditions for 15 hr by shock cooling (within 3 minutes) down to – 20 ± 3°C,1-day conditioning in room conditions (23°C, 50% RH).