Thermal Analysis of an Anti-Ice System.

 

The structure to be analyzed is a shut-off  and pressure-reducing valve  employed in the anti-ice system of  aircrafts. Essentially two main bodies compose this device: the valve itself and its external actuator. The valve is made of Inconel 718 and is heated by the air flowing at a temperature of about 600 °C. A titanium bracket, mounted externally to the valve, supports the lever mechanism of the shut-off module and the hydraulic actuator. This device is constituted by a piston, an LVDT transducer, a solenoid and a servo-valve, which control the flux of fuel driving the piston.

As seen, the actuator is operated by the fuel circuit of the aircraft. Obviously there are some limitations on the temperature of the fuel returned to the outlet port and on the heat that can be transferred to the components. The finite element model employs tetrahedral thermal solid and shell elements. Most thermal properties are temperature dependent so, the analysis is steady-state and non-linear. The bulk temperature of the air surrounding all convection surfaces is 162 °C. The model takes into account the heat generation rate of the solenoid and the heat flux transferred to the fuel. The amount of heat across the surfaces exposed to fuel is adjusted with a trial-and-error procedure.