1. 7mm, afurther reduction to 0.5mm is deemed tobe realistic. Limiting factors for the wall thickness are manufacturing tolerances and material grain size. In order to see the pure effect of a wall thickness reduction, the configuration in has been defined. Configuration HEcompares directly to configuration II. The only difference between both configurations is thereduced hot gas wall thicknessof configuration ffl (0.5mm). A fourth - hypothetical - configuration IV has been introduced by further increasing the number of cooling channels by afactor of 2.75 and keeping the wall thickness constant in comparison to the reference configuration. The dimensionsof the configuration IV (cooling channel width 0.3mm and fin thickness 0.2 mm in combination with anaspectratio of =10) are, however, beyond the manufacturing limits. The confguration V bases on the same overall geometrical cooling channel envelope (total number of cooling channels, cooling channel width and fin thickness, cooling channel height adapted for constant Ap assumption) as the reference design of configuration I. The major difference between the configurations I and V is the structure of the cooling channel bottom. In contrast to configuration I with a smooth surface, the cooling channel bottom of configuration Visequipped withmicroscopicdimensional triangularfins inflow direction.
2. tionary cavity-to-nozzle position and the asymptotic nature of the temperature evolution, rise times to maximum temperature culd only be indicated roughly 30 -50 s, andshowed nosignificant
3. droptoratesof 20-40K/S •.no ignition was achieved during the mixed gas
4. TMI no.: F970130 - 02