Annular Combustion Chamber Wall Cooling Orifice Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Turbomachine combustion chamber walls experience inadequate cooling and risk of crack formation downstream of primary and dilution holes due to limitations in existing laser drilling technologies, leading to increased manufacturing costs and time with localized transition hole solutions.
Innovation Solution
An annular combustion chamber wall design featuring additional cooling orifices arranged in inclined planes perpendicular to the flow direction, with specific inclinations of 30° and 60°, to enhance cooling efficiency and reduce thermal gradients without altering the primary flow, incorporating a gyratory-axial multi-perforation transition zone to smooth flows and prevent crack initiation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional laser drilling technology is used for cooling holes, then manufacturing cost and time are reduced, but inadequate cooling and crack formation occur downstream of primary and dilution holes
Solution Approach 1:
The patent applies different hole configurations in different zones of the annular wall: conventional multi-perforation holes in most areas, and specific additional cooling holes with different inclination angles (30° and 60°) directly downstream of primary and dilution holes. This local differentiation provides enhanced cooling exactly where thermal gradients are highest without unnecessarily complicating the entire wall structure.
Solution Approach 2:
The cooling system is segmented into multiple functional zones: primary cooling holes for general wall cooling, additional cooling holes with 30° inclination for upstream transition zone cooling, and additional cooling holes with 60° inclination for downstream zone cooling. Each segment addresses specific thermal management needs in its designated area.
2Reliability
If additional cooling holes with different inclinations are added, then cooling effectiveness improves, but manufacturing time and cost increase
Solution Approach 1:
The patent modifies specific parameters (hole inclination angles) only in critical zones rather than changing the entire cooling system. The additional cooling holes are drilled at specific angles (30° and 60°) only where needed downstream of primary and dilution holes, maintaining standard parameters elsewhere to preserve manufacturing efficiency.
Solution Approach 2:
Enhanced cooling with varied hole inclinations is applied locally only in zones experiencing high thermal gradients downstream of primary and dilution holes, rather than uniformly across the entire annular wall, thus limiting the additional manufacturing complexity to only where it provides value.
3Reliability
If localized transition hole treatment is applied, then cooling at critical areas improves, but manufacturing cost and time significantly increase
Solution Approach 1:
The patent provides targeted crack prevention by placing additional cooling holes with specific inclinations (30° upstream, 60° downstream) only in the transition zones directly downstream of primary and dilution holes where thermal gradients are highest, rather than applying expensive localized treatment across entire critical areas.
Solution Approach 2:
The wall is divided into zones with different cooling requirements: standard multi-perforation zones and enhanced cooling zones with additional holes at specific inclinations. This segmentation allows cost-effective manufacturing by applying complex hole patterns only where crack prevention is critical.
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 solution ensures effective cooling of critical areas downstream of primary and dilution holes, reducing thermal gradients and preventing crack formation while maintaining flow efficiency and reducing manufacturing costs by smoothing flow profiles and improving mixing.
Implementation Method 1
a plurality of cooling orifices to allow air circulating on the cold side of said annular wall to enter the hot side in order to form a cooling air film along said annular wall
Implementation Method 2
the geometric axes of each of said cooling orifices being inclined, in an axial direction D of combustion gas flow, at an angle of inclination θ1 with respect to a normal N to said annular wall
Implementation Method 3
a plurality of additional cooling orifices arranged directly downstream of said primary or dilution holes and distributed in a plurality of circumferential rows spaced axially apart from each other; the geometric axes of each of said additional cooling orifices being arranged in a plane perpendicular to said axial direction D
Implementation Method 4
at the level of a transition zone formed directly downstream of said plurality of rows of additional orifices and directly upstream of said plurality of rows of cooling orifices, exactly two rows of orifices whose geometric axes of each of said orifices are inclined respectively at 30° and 60°
Data Source
Figure 1
Figure 2~3
AI summary
Annular combustion chamber wall (10) of turbomachine, having a cold side (16a, 18a) and a hot side (16b, 18b), a plurality of primary or dilution holes (30) distributed in a circumferential row to allow air circulating from the cold side (16a, 18a) of the annular wall to enter the hot side (16b, 18b) in order to ensure the dilution of an air/fuel mixture;and a plurality of cooling orifices (32) to allow air circulating on the cold side (16a, 18a) of the annular wall to enter on the hot side (16b, 18b) in order to form a cooling air film along the annular wall, the cooling orifices being distributed in a plurality of circumferential rows spaced axially apart from each other and the geometric axes of each of the cooling orifices being inclined, in an axial direction D of combustion gas flow, at an angle of inclination θ1 with respect to a normal N to the annular wall;the wall further comprising a plurality of additional cooling orifices (34) arranged directly downstream of the dilution holes and distributed in a plurality of circumferential rows spaced axially apart from each other, the geometric axes of each of the additional cooling orifices being arranged in a plane perpendicular to the axial direction D and inclined at an angle of inclination θ2 with respect to a normal N to the annular wall, and at the level of a transition zone (28B, 30B) formed downstream of the plurality of rows of additional orifices, at least two rows of orifices whose geometric axes of each of the orifices are inclined, with respect to a plane perpendicular to the axial direction D, at a determined inclination different for each of the two rows.;