Nozzle Head Guide Elements for Combustion Backflow Prevention
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Solution Overview
Problem
Existing nozzle assemblies for combustion chambers in engines often experience backflow of hot gases due to recirculation zones, leading to overheating and potential destruction of the nozzle head.
Innovation Solution
A nozzle assembly with a nozzle head featuring protruding guide elements on its outer lateral surface, which deflects a part of the swirl-affected air flow radially inward, creating a central injection region downstream of the nozzle exit opening and effectively counteracting backflow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If a recirculation zone is created downstream of the nozzle exit opening to ensure flame stability, then flame stability is improved, but hot gases backflow to the nozzle head causing overheating and potential destruction
Solution Approach 1:
The air flow is segmented into two distinct paths: a swirl-affected outer air flow that creates the recirculation zone for flame stability, and a guide element-directed inner air flow that moves axially to counteract hot gas backflow. This segmentation allows each air flow path to perform its specific function without interfering with the other, resolving the contradiction between flame stability and backflow prevention
Solution Approach 2:
Different regions of the air flow are given different qualities: the outer region receives swirl to create recirculation for flame stability, while the inner region is directed axially through guide elements to prevent backflow. This local differentiation of air flow characteristics allows simultaneous achievement of flame stability and backflow protection
2Object-affected harmful factors
If guide elements are added to the nozzle head to direct air flow radially inwards and counteract backflow, then backflow prevention is improved, but device complexity increases
Solution Approach 1:
The guide elements utilize the existing swirl-affected air flow from the air-guiding ducts and redirect it to serve the additional function of counteracting backflow. The system serves itself by using its own air flow to achieve backflow protection, avoiding the need for separate active control systems or additional energy input mechanisms
Solution Approach 2:
The air-guiding ducts serve multiple functions: they deliver air for mixing with fuel, create swirl for recirculation zone formation, and through the guide elements, direct axial flow to prevent backflow. This multi-functionality reduces the need for separate components, thereby limiting the increase in device complexity
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 proposed solution effectively prevents backflow of hot gases to the nozzle head, reducing the risk of overheating and nozzle head destruction, while maintaining flame stability through the recirculation zone.
Implementation Method 1
at least one guide element, which protrudes on the outer lateral surface of the nozzle head, is additionally obtained that guides at least a part of the air flow radially inwards (to a greater extent) into an injection region, which is central in the injection direction, downstream of the nozzle exit opening
Implementation Method 2
In the process, the partial air flow can also be slowed down in the circumferential direction, with the result that less rotational energy is inherent to the partial air flow and thus this part (which is guided radially inwards to a greater extent) of the air flow from the air-guiding duct is less swirl-affected
Implementation Method 3
These air flows usually lead to the input of swirled air and thus to the production of eddy currents and thus a recirculation zone at the nozzle exit opening, which is necessary for flame stability
Implementation Method 4
this makes it possible to effectively counteract a backflow of hot gases in the direction of the nozzle exit opening and thus at the nozzle head
Data Source
AI summary
The proposed solution relates to a nozzle assembly for a combustion chamber of an engine, havingat least one nozzle, which includes a nozzle head that extends along a nozzle longitudinal axis and has at least one nozzle exit opening for injecting fuel into a combustion space of the combustion chamber, andat least one air-guiding duct, by way of which a swirl-affected air flow can be created in the direction of the combustion space along an outer lateral surface of the nozzle head.At least one guide element which protrudes on the outer lateral surface of the nozzle head is in a flow path for the air flow of the at least one air-guiding duct and is configured to guide at least a part of the air flow radially inwards in relation to the nozzle longitudinal axis into a central injection region downstream of the nozzle exit opening.