Aircraft Fuel Blending for Contrail and Soot Control
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Solution Overview
Problem
Existing methods to reduce vapour trail formation from engine exhausts, such as using ultra-low sulphur fuel, heat exchangers, electromagnetic energy, ultrasound, and chemical additives, incur weight, fuel, or pollution penalties, and do not effectively optimize fuel use while minimizing climate warming impact.
Innovation Solution
A fuel system that selectively blends two fuels on demand using a fluid blender and regulator, controlled by sensors and a soot requirement generator, to adjust the soot emission index and reduce vapour trail optical depth based on ambient conditions and engine operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If heat exchanger and condenser arrangement are used to suppress vapour trail formation, then vapour trail formation is reduced, but significant weight is introduced into the engine
Solution Approach 1:
The patent extracts only the essential function of vapour trail suppression by using a simplified condenser arrangement that removes water vapour from exhaust gases without requiring complex heat exchanger systems. This extraction approach reduces the weight penalty while maintaining the core benefit of reduced vapour trail formation.
Solution Approach 2:
The patent introduces an intermediary substance (condensate water) that mediates between the exhaust gases and the environment. By condensing water vapour into liquid form and separating it, the system achieves vapour trail suppression without requiring heavy thermal management equipment, thus resolving the weight contradiction.
2Object-affected harmful factors
If directed electromagnetic energy is used to suppress vapour trail formation, then vapour trail formation is reduced, but weight penalty and significant fuel-burn penalty are incurred
Solution Approach 1:
The patent replaces the proposed electromagnetic energy system with a passive thermal condensation mechanism. By using the natural cooling effect of ambient air flowing over exhaust gases, the system achieves vapour trail suppression without requiring active electromagnetic energy input, thereby eliminating the fuel-burn penalty associated with electromagnetic systems.
Solution Approach 2:
The condenser arrangement utilizes the engine's own airflow and ambient air to achieve cooling and condensation. The system is self-servicing by using the vehicle's motion-induced airflow to remove heat from exhaust gases, eliminating the need for external energy input and reducing overall fuel consumption.
3Object-affected harmful factors
If ultrasound directed into engine exhaust plume is used to suppress vapour trail formation, then vapour trail formation is reduced, but material weight penalty is incurred
Solution Approach 1:
The patent replaces the complex ultrasound generation and delivery system with a passive aerodynamic condensation system. By using airflow management and thermal exchange surfaces, the system achieves vapour trail suppression without requiring heavy ultrasound equipment, thus resolving the weight contradiction.
4Object-affected harmful factors
If chemical additives are injected into engine or exhaust plume to modify vapour trails, then vapour trail formation is suppressed, but additional pollution and weight penalty are incurred
Solution Approach 1:
The patent converts the naturally occurring water vapour in exhaust gases, which normally forms visible vapour trails, into a beneficial condensed liquid that can be easily separated and removed. By utilizing the condensation process, the system transforms the harmful visible trail into a manageable liquid condensate, achieving suppression without introducing additional pollutants from chemical additives.
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
This approach allows for dynamic control of vapour trail optical depth, reducing climate warming impact while optimizing fuel use, with minimal weight and power penalties, and enabling aircraft to maintain optimal flight trajectories and reduce airspace congestion.
Implementation Method 1
a fluid blender in fluid communication with a source of a first fuel composition and a source of a second fuel composition via at least one inlet, the blender being configured to receive at least the first fuel composition and/or second fuel composition via the at least one inlet and output a resultant fuel composition comprising the received fuel compositions
Implementation Method 2
The attempted suppression of vapour trail formation through the reduction of exhaust water vapour content through use of a heat exchanger and condenser arrangement
Data Source
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AI summary
A method of providing fuel to an engine (12) during a period of operation of the engine. Ambient air conditions are determined in dependence upon actual measured values of ambient air conditions. The likelihood of vapour trail formation and/or vapour trail persistence is determined based upon engine operating point and the determined ambient air conditions. A desired soot emission index is determined. A fuel blender (14) is operated in fluid communication with a source of a first fuel composition and a source of a second fuel composition via at least one inlet (32, 34). A required resultant fuel composition is calculated as a function of the desired soot emission index, the required resultant fuel composition defining a percentage of the first and second fuel composition for blending together. The fuel blender mixes said percentages of first fuel composition and second fuel composition to produce the required resultant fuel composition for output to an engine via at least one outlet (36).