Multiphase Fuel Injector with Dual Swirling Circuits for Uniform Atomization
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Solution Overview
Problem
Conventional variable-area fuel injectors suffer from non-uniform fuel distribution, leading to thermal distress, poor emissions, and reduced efficiency in air-breathing engines, and poor performance in automotive exhaust treatment and missile applications due to inadequate spray circumferential uniformity and high fuel turndown ratios.
Innovation Solution
A multiphase fuel injector with dual circuits, featuring a primary circuit for improved atomization and a secondary circuit for high flow rates, utilizing additive manufacturing to create helical openings for swirling motion, eliminating moving components like pintles and requiring fewer manufacturing and operational complexities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional variable-area fuel injectors use slots or holes to feed fuel to the fuel manifold, then the injector structure is simple, but the fuel distribution becomes non-uniform causing hot spots and thermal distress
Solution Approach 1:
The fuel injector is divided into multiple independent circuits (primary and secondary circuits) with separate fuel delivery paths. Each circuit has its own set of openings arranged in a specific pattern, allowing independent control of fuel flow to different zones of the combustion chamber. This segmentation prevents wake formation and ensures uniform fuel distribution across all zones, eliminating hot spots while maintaining manufacturing simplicity through modular design.
2Device complexity
If conventional variable-area fuel injectors use a single circuit, then the device complexity is low, but the fuel turndown ratio is insufficient for wide operational ranges
Solution Approach 1:
The single fuel inlet is divided into multiple independent circuits (primary and secondary circuits), each capable of operating independently or in combination. The primary circuit handles low-flow conditions with optimized openings for precise metering, while the secondary circuit handles high-flow conditions with larger openings. This segmentation enables a wide fuel turndown ratio (150:1) without requiring complex additional components, as each circuit is simple in design but collectively they provide extensive operational range.
Solution Approach 2:
The fuel flow distribution between primary and secondary circuits is dynamically adjusted based on operating conditions through pressure-sensitive flow control. At low fuel pressures, the primary circuit dominates fuel delivery; as pressure increases, the secondary circuit progressively opens to handle higher flow rates. This dynamic switching between circuits enables adaptation to wide operational ranges while maintaining simple circuit designs without active control mechanisms.
3Manufacturing precision
If conventional fuel injectors lack swirling motion, then the atomization is inadequate, but adding moving parts increases device complexity
Solution Approach 1:
Helical (curved) openings are incorporated into the primary and secondary circuits instead of straight openings. The helical geometry imparts a swirling motion to the fuel flow as it passes through the circuits, creating rotational velocity that enhances atomization quality. This curvature-based approach generates the desired swirling flow pattern without requiring any moving parts, maintaining device simplicity while significantly improving fuel atomization and spray circumferential uniformity.
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 multiphase fuel injector achieves high accuracy, reliable light-off, and rapid transition to maximum power with a turndown ratio of 150, providing consistent performance and improved atomization across a wide range of flow rates without moving parts.
Implementation Method 1
The primary circuit is configured to impart a swirling action to the first flow of pressurized fuel. The secondary circuit is configured to impart a swirling action to the second flow of pressurized fuel.
Implementation Method 2
receive a first flow of pressurized fuel from the fuel inlet and discharge the fuel into a spin chamber
Data Source
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AI summary
A multiphase fuel injector has an injector body with a fuel inlet at a first end and a fuel outlet at a second end opposite the first end. A primary circuit disposed proximate the fuel inlet extends into a central portion of the injector body. The primary circuit is configured to receive a first flow of pressurized fuel from the fuel inlet that discharges into a spin chamber in the injector body downstream from the fuel inlet. The primary circuit is configured to impart a swirling action to the first flow of pressurized fuel. A secondary circuit is located in the injector body radially outward from the primary circuit. The secondary circuit is configured to receive a second flow of pressurized fuel from the fuel inlet that discharges into the fuel outlet. The secondary circuit is configured to impart a swirling action to the second flow of pressurized fuel.