Patent Description:
Gas turbine engines use a combination pressure and temperature probe to measure pressure and temperature at an inlet of the gas turbine engine. Such a probe is commonly referred to as a P2T2 probe.

The probe typically includes a housing that protrudes into an inlet air stream of the gas turbine engine. The housing may have an aerodynamically efficient shape to reduce airflow disturbances in the inlet. A temperature sensing element is located in the housing, with an airflow inlet in the housing to supply airflow to the temperature sensing element. The airflow around the temperature sensing element plays a major role in the response time of temperature sensing. Generally, with increased airflow, the response time is decreased. <CIT> relates to probes which simultaneously measure temperature and pressure of a moving gas stream. The pressure and temperature probe has a low drag, an airfoil shaped cross section and includes longitudinally extending pressure cavities adjacent the leading edge and separate longitudinally extending temperature cavity immediately downstream thereof.

In one embodiment, a pressure and temperature probe of a gas turbine engine includes a base portion, an end portion surface, and an airfoil portion extending from the base portion to the end portion surface located at a distal end of the probe. The airfoil portion includes a leading edge located at an upstream end of the probe relative to a direction of airflow across the probe. A temperature sensor is located in a temperature sensor chamber located in the airfoil portion, and a temperature airflow hole at the distal end of the airfoil portion through the end portion surface and is configured to admit an airflow into the temperature sensor chamber around the temperature sensor. The temperature airflow hole is configured and positioned such that the airflow admitted via the temperature airflow hole has a turning angle of less than <NUM> degrees into the temperature sensor chamber.

Additionally or alternatively, in this or other embodiments the temperature sensor extends along a sensor central axis in the temperature sensor chamber, and the temperature airflow hole has an airflow hole central axis offset from the sensor central axis in a streamwise direction.

Additionally or alternatively, in this or other embodiments the airflow hole central axis is located upstream of the sensor central axis.

Additionally or alternatively, in this or other embodiments the airflow hole central axis is offset from the sensor central axis by between <NUM> and <NUM> times a diameter of the temperature airflow hole.

Additionally or alternatively, in this or other embodiments the end portion surface includes a first end portion surface, and a second end portion surface sloped toward the base portion relative to the first end portion surface with increasing distance from the leading edge. The temperature airflow hole is located at the second end portion surface.

Additionally or alternatively, in this or other embodiments the slope is one of a constant angle, a varying angle or a curvilinear slope.

Additionally or alternatively, in this or other embodiments a slope angle of the second end portion surface relative to the first end portion surface is between <NUM> and <NUM> degrees.

Additionally or alternatively, in this or other embodiments a sensor slot is located along the airfoil portion as a secondary source of airflow to the temperature sensor chamber.

Additionally or alternatively, in this or other embodiments an inlet of a gas turbine engine includes a casing having an casing inner wall thereby defining an inlet flowpath, and one or more of the pressure and temperature probes extending inwardly from the casing inner wall toward an engine central longitudinal axis.

Additionally or alternatively, in this or other embodiments the temperature sensor extends along a sensor central axis in the temperature sensor chamber, and the temperature airflow hole has an airflow hole central axis offset from the sensor central axis in a streamwise direction such that the airflow hole central axis is located upstream of the sensor central axis.

Additionally or alternatively, in this or other embodiments a gas turbine engine includes a fan driven by a turbine of the gas turbine engine, and the inlet is located upstream of the fan.

The fan section <NUM> includes an inlet portion <NUM>, defined by a casing <NUM> extending upstream of a fan <NUM> of the fan section <NUM>.

Referring to <FIG>, one or more probes <NUM> extend radially inwardly toward an engine central longitudinal axis A from an interior casing surface <NUM> of the casing <NUM>. In some embodiments, the probe <NUM> is a pressure and temperature probe configured to detect a pressure and temperature at the inlet portion <NUM>. Such a probe is also referred to as a P2T2 probe. Referring to <FIG>, the probe <NUM> includes a base portion <NUM> located at the interior casing surface <NUM>, and an airfoil portion <NUM> extending from the base portion <NUM> radially inwardly toward the engine central longitudinal axis A. The airfoil portion <NUM> includes a leading edge <NUM> and a trailing edge <NUM>, with the leading edge <NUM> located upstream of the trailing edge <NUM>, relative to a general direction of airflow <NUM> into the inlet portion <NUM>. A first side <NUM> and a second side <NUM> opposite the first side <NUM> each extend from the leading edge <NUM> to the trailing edge <NUM>. An end portion <NUM> of the probe <NUM> is located at a distal end of the airfoil portion <NUM>, furthest from the base portion <NUM>. A temperature sensor <NUM> is located in a temperature sensor chamber <NUM> inside of the airfoil portion <NUM> of the probe <NUM>. To provide airflow to the temperature sensor <NUM>, a temperature airflow hole <NUM> is provided through the end portion <NUM> as a primary source of airflow <NUM> into the temperature sensor chamber <NUM>. In some embodiments, the temperature airflow hole <NUM> has a circular cross-section. Further, an airflow slot <NUM> is provided in one or more of the first side <NUM> or the second side <NUM> as a secondary source of airflow to the temperature sensor chamber <NUM>. In some embodiments, an airflow slot <NUM> length in a direction from the base portion <NUM> toward the end portion <NUM> is greater than a streamwise airflow slot <NUM> width. In some embodiments, a pressure airflow inlet <NUM> is located at the leading edge <NUM> to admit a pressure measurement airflow into the probe <NUM>.

Referring now to <FIG>, the temperature sensor <NUM> extends along a sensor central axis <NUM> in the temperature sensor chamber <NUM>. In some embodiments, the temperature sensor chamber <NUM> is symmetrical about the sensor central axis <NUM>. In some embodiments, the temperature airflow hole <NUM> is offset from the sensor central axis <NUM>, such that an airflow hole central axis <NUM> is not coaxial with the sensor central axis <NUM>. In particular, the temperature airflow hole <NUM> is offset in a streamwise direction, such that the airflow hole central axis <NUM> is nearer to the leading edge <NUM> of the airfoil portion <NUM> than the sensor central axis <NUM>. In some embodiments, an offset distance <NUM> is between about <NUM> and <NUM> of a diameter of the temperature airflow hole <NUM>. The offset of the temperature airflow hole <NUM> from the sensor central axis <NUM> improves airflow through the temperature airflow hole <NUM> by reducing a turning angle of airflow into temperature sensor chamber <NUM> via the temperature airflow hole <NUM> to less than <NUM> degrees, thus improving airflow into the temperature sensor chamber <NUM> and response of the temperature sensor <NUM>.

In another embodiment, illustrated in <FIG>, the end portion <NUM> includes a first end portion surface <NUM> and a second end portion surface <NUM>. The second end portion surface <NUM> is located upstream of the temperature airflow hole <NUM> relative to the streamwise direction. The second end portion surface <NUM> is sloped away from the first end portion surface <NUM> toward the base portion <NUM> with a decreasing distance from the temperature airflow hole <NUM>. The temperature airflow hole <NUM> is located along the second end portion surface <NUM>. In some embodiments, the second end portion surface <NUM> is sloped at a constant slope angle <NUM> relative to the first end portion surface <NUM>, while in other embodiments other configurations such as a slope having a varying angle or a curvilinear sloping of the second end portion surface <NUM> may be utilized. In some embodiments, the slope angle <NUM> is between <NUM> degrees and <NUM> degrees, while in other embodiments the slope angle <NUM> is between <NUM> degrees and <NUM> degrees.

The use of the sloping second end portion surface <NUM> reduces a turning angle of airflow <NUM> into the temperature airflow hole <NUM> to below <NUM> degrees thus resulting in greater airflow through the temperature airflow hole <NUM> and into the temperature sensor chamber <NUM>. In some embodiments, the sloping end portion <NUM> may be used in combination with the offset of the temperature airflow hole <NUM>. The configurations disclosed herein improve airflow into the temperature sensor chamber <NUM> without reducing aerodynamic performance of the airflow portion <NUM> of the probe <NUM>.

Claim 1:
A pressure and temperature probe of a gas turbine engine (<NUM>), comprising:
a base portion (<NUM>);
an end portion surface (<NUM>);
an airfoil portion (<NUM>) extending from the base portion to the end portion surface (<NUM>) located at a distal end of the probe, the airfoil portion including a leading edge (<NUM>) disposed at an upstream end of the probe relative to a direction of airflow across the probe (<NUM>);
a temperature sensor (<NUM>) disposed in a temperature sensor chamber (<NUM>) located in the airfoil portion; and
a temperature airflow hole (<NUM>) at the distal end of the airfoil portion through the end portion surface (<NUM>), the temperature airflow hole being configured to admit an airflow (<NUM>) into the temperature sensor chamber around the temperature sensor, the temperature airflow hole configured and positioned such that the airflow admitted via the temperature airflow hole has a turning angle of less than <NUM> degrees into the temperature sensor chamber.