The present liquid third safety is considered undesirable for the piles at their present power levels. Any increase in power level and graphite temperature makes the need for an alternative third safety increasingly imperative. The use of the third safety is envisioned under conditions where the supply of cooling water to an operating pile is interrupted and concurrently the safety rods full to enter the pile because of slight shifting of the top shield or larger shifting of the winches, relative to the pile proper. Under these conditions, undesirable properties of a liquid third safety are present and are discussed in this memorandum.

From Introduction: "Data are presented to show the effects of tail-pipe fuel-air ratio, altitude, and flight Mach number on tail-pipe-burner performance at rated engine speed and approximately constant turbine-outlet temperature. Operational characteristics of the tail-pipe burner and variable-area exhaust nozzle are also reported."

An equation for average heat transfer of a surface was derived when the boundary layer changed from laminar to turbulent. Influences on the heat transfer through a laminar boundary layer of Mach number, temperature ratio (gas temperature divided by wall temperature), and exponents of gas-property temperature relations were shown to be relatively small for air with Mach numbers less than 2 and temperature ratios between 1 and 4. Good agreement was obtained with experimental results from cylinders, an airfoil, and turbine blades.

Analytical methods are presented for the determination of local values of outside and inside heat-transfer coefficients and effective gas temperatures by use of turbine-blade-temperature measurements. The methods are derived for a number of configurations that can be applied to typical cooled-turbine-blade shapes as well as to other types of heat-transfer apparatus.