Hoop Ejector Airflow Induction for TAT Probe Radiation Error Reduction
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Solution Overview
Problem
Total air temperature (TAT) probes on aircraft are susceptible to radiation errors when stationary and exposed to direct sunlight, leading to inaccurate temperature readings due to increased temperature within the probe.
Innovation Solution
A hoop ejector with angled holes is integrated into the TAT probe, creating a pressure differential to induce airflow through the probe, reducing solar radiation effects and maintaining accurate readings by aspirating air and reducing pressure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the TAT probe is stationary and exposed to direct sunlight, then the temperature of the probe and air inside increases, but this causes radiation error and inaccurate temperature readings
Solution Approach 1:
The system performs preliminary action by using the hoop ejector to induce airflow through the TAT probe before radiation error significantly affects measurements. The compressed air supply activates the hoop ejector proactively to maintain accurate readings during sunlight exposure, preventing temperature distortion rather than correcting it afterward.
Solution Approach 2:
The invention applies pneumatic principles by using compressed air supplied to the hoop ejector to create airflow induction. The hoop ejector utilizes pneumatic pressure differential to draw air through the probe, replacing natural convection that causes radiation error with controlled pneumatic flow that maintains measurement accuracy.
2Weight of stationary object
If the TAT probe is designed to be smaller and lighter, then the device complexity is reduced, but it may compromise the ability to maintain accurate readings under radiation exposure
Solution Approach 1:
The hoop ejector serves multiple functions: it induces airflow through the probe for accurate temperature measurement, and simultaneously cools the probe structure to prevent radiation-induced heating. This multi-functionality allows the probe to maintain reliability and accuracy under radiation exposure without requiring additional separate cooling systems that would increase weight.
3Measurement precision
If airflow is induced through the probe using a hoop ejector, then solar radiation effects are reduced, but this requires additional components and compressed air supply
Solution Approach 1:
The hoop ejector acts as an intermediary device between the compressed air supply and the TAT probe. It translates compressed air pressure into controlled airflow induction through the probe, mediating the interaction between the external air supply system and the sensitive temperature measurement components, thereby improving measurement precision without directly complicating the probe's internal structure.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The hoop ejector effectively reduces solar radiation errors by up to 95%, ensuring more accurate temperature readings without altering the internal geometry of the TAT probe, allowing it to be smaller and lighter.
Implementation Method 1
A hoop ejector with angled holes is integrated into the TAT probe, creating a pressure differential to induce airflow through the probe
Implementation Method 2
aspirating air and reducing pressure
Implementation Method 3
The plurality of holes extend from an outer diameter of the inner wall of the hoop to an inner diameter of the inner wall of the hoop at an angle... The holes are configured to speed up the velocity of air as air passes through the holes and lower the pressure of air as air passes through the holes
Data Source
Figure 1A
Figure 1B
Figure 2A
AI summary
A probe (10) includes a housing (14) defining a flow passage (24) for a first fluid and having an entrance port (20) and an exit port (30), a sensor configured to sense a parameter of the first fluid and positioned within the flow passage (24), and a hoop ejector (12) connected externally to the housing (14) such that a channel (54) of the hoop ejector (12) surrounds the exit port (30). The hoop ejector (12) has a plurality of holes (58) configured to port a second fluid from the channel (54) such that the first fluid is aspirated from the flow passage (24) and out through the exit port (30).