This disclosure relates to a flow meter for use in a cooling fluid system of a gas turbine engine.
A gas turbine engine typically includes a fan section, a compressor section, a combustor section and a turbine section. Air entering the compressor section is compressed and delivered into the combustor section where it is mixed with fuel and ignited to generate a high-speed exhaust gas flow. The high-speed exhaust gas flow expands through the turbine section to drive the compressor and the fan section. The compressor section typically includes low and high pressure compressors, and the turbine section includes low and high pressure turbines.
The turbine section is subjected to hot temperatures during engine operation. Typically, a cooling fluid, such as compressor bleed air, is provided to the turbine section to cool various components and provide pressurized fluid for other purposes.
In one example, the cooling fluid system includes four pipes from the high pressure compressor section that supply cooling air to mid-turbine frame vanes through fluid fittings. Smaller pipes are secured to the fluid fitting to a supply cooling fluid to I-rods that run radially through some of the mid-turbine frame vanes.
Airflow to the mid-turbine frame vanes and the I-rods is metered to provide a desired balance of cooling fluid to each location. Typically, a metering plate is bolted between the fluid fitting and the outer case of the turbine section. As a result, this metering plate is downstream from the smaller pipes supplying cooling fluid to the I-rods. Additionally, typically an unequal amount of smaller pipes are secured to each of the fittings. In one of the examples, each of two fluid fittings have three smaller pipes, one fluid fitting has two smaller pipes. The fourth fluid fitting has no smaller pipes, but feeds only one of the mid-turbine frame vanes.