Jet Temperature Estimation Using Digital Modeling and Error Correction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for estimating the temperature of gas flows in turbojets are hindered by the inertia of temperature sensors, leading to time lags and malfunctions, especially during rapid temperature variations, and are costly due to the need for expensive low-inertia sensors and complex correction techniques that do not accurately account for sensor dispersion.
Innovation Solution
A method that uses digital modeling of vein temperature, corrected by an error signal updated during thermal stability phases, allowing for precise estimation of vein temperature using low-cost sensors with high time constants, and adaptive algorithms to account for different operating phases of the turbojet.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If temperature sensors with very low inertia are used to avoid time lags and malfunctions during rapid temperature variations, then measurement reliability is improved, but sensor cost increases significantly
Solution Approach 1:
The patent creates a virtual copy of the temperature measurement system through digital modeling. Instead of physically modifying the sensor to reduce inertia, the system digitally models the sensor's thermal behavior and uses this model to predict and correct measurement delays, thereby achieving reliable temperature estimation without expensive low-inertia sensors
Solution Approach 2:
The patent replaces the physical mechanical solution (using low-inertia sensors) with a computational approach. By substituting the physical sensor modification with digital modeling and signal processing, the system achieves the same reliability improvement without the associated cost increase
2Measurement precision
If numerical modeling with filter parameterization is used to correct measurement signals, then measurement precision is improved, but device complexity increases due to additional estimators and complex correction techniques
Solution Approach 1:
The patent uses digital modeling to create a virtual representation of the temperature measurement system, allowing complex corrections to be applied computationally rather than requiring complex physical hardware modifications
Solution Approach 2:
The system uses the modeled signal itself to generate the correction. By comparing the modeled temperature evolution with actual measurements, the system automatically adjusts the error signal without requiring external calibration or complex additional estimators
3Ease of operation
If fixed charts based on average time constant values are used for correction, then ease of operation is improved, but measurement precision deteriorates due to sensor inertia dispersion not being accounted for
Solution Approach 1:
The patent transitions from static fixed charts to a dynamic adaptive model. The digital model continuously adapts to the specific sensor's characteristics by learning from actual measurements during operation, allowing the system to account for sensor inertia dispersion while maintaining operational simplicity
Solution Approach 2:
The system changes the approach from using fixed average parameters to dynamically adjusting parameters based on actual sensor behavior. The error signal is continuously updated to reflect the specific sensor's time constant characteristics, improving precision without complicating operation
4Measurement precision
If wind tunnel testing is performed to determine time constant for each sensor, then measurement precision is improved, but manufacturing cost increases significantly
Solution Approach 1:
The patent replaces expensive physical wind tunnel testing with a computational digital model that can estimate time constants in-situ during normal engine operation, eliminating the need for costly external testing facilities
Solution Approach 2:
The system performs its own calibration by using actual engine operation data to determine sensor characteristics. Instead of requiring external testing, the sensor's time constant is automatically identified during normal operation through comparison of modeled and actual temperature signals
Data Source
Figure 1~2
Figure 3
Figure 4~5
AI summary
The estimation method according to the invention includes: a step of digitally modeling the jet temperature by means of a modeled signal (T1); and a step of correcting said modeled signal by means of an error signal (T2), the signal being obtained after correction (T3) representing an estimate of the jet temperature. According to the invention, when predetermined conditions related to at least one jet engine operating phase and to thermal stability are verified, the error signal (T2) is updated on the basis of the modeled signal (T1) and a jet temperature measurement signal (T4) produced by a temperature sensor (40).