HPDI Diesel-Gas Piston with Omega Bowl and Jet Splitter
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Solution Overview
Problem
Current piston geometries for HPDI diesel gas internal combustion engines do not effectively optimize engine efficiency and reduce exhaust emissions, particularly in the commercial vehicle sector, due to inadequate design for gaseous fuel and diesel fuel mixture formation and combustion processes.
Innovation Solution
A piston geometry featuring an omega piston bowl with multiple annularly arranged piston steps and a jet splitter contour that divides fuel into two partial flows, allowing for adjustable turbulence and optimized mixture formation and combustion through targeted fuel routing and flow separation edges.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional piston geometries are used in HPDI diesel gas engines, then the engine structure is simple, but engine efficiency is insufficient and exhaust emissions are high
Solution Approach 1:
The piston crown is divided into multiple functional zones including a central piston bowl, an annular piston step, and an omega-shaped recess with jet splitter contour. This segmentation allows different regions to perform specialized functions: the piston bowl for fuel accumulation and initial mixing, the piston step for flow direction control, and the omega recess with jet splitter for turbulence generation and secondary mixing, collectively improving combustion efficiency and reducing emissions
Solution Approach 2:
Each region of the piston crown is designed with specific geometric characteristics optimized for its local function. The piston bowl has a specific depth and diameter ratio for optimal fuel pooling, the piston step has precise height and radius measurements for controlled flow separation, and the omega recess features a jet splitter contour with specific curvature for enhanced turbulence. These localized geometric optimizations ensure efficient mixture formation and combustion in each zone
2Productivity
If piston geometry is optimized for mixture formation, then combustion efficiency improves, but device complexity increases
Solution Approach 1:
Multiple functional features are merged into a single integrated piston crown structure. The piston bowl, piston step, omega-shaped recess, and jet splitter contour are combined in one component rather than being separate parts, achieving complex mixture formation and combustion optimization while maintaining manufacturing feasibility through unified piston crown machining
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 design enhances engine efficiency and reduces emissions by improving air-fuel-diesel mixture generation and combustion speed, minimizing glow ignition and utilizing available oxygen, thereby achieving high efficiency and low raw emissions.
Implementation Method 1
A piston geometry featuring an omega piston bowl with multiple annularly arranged piston steps and a jet splitter contour that divides fuel into two partial flows, allowing for adjustable turbulence and optimized mixture formation and combustion through targeted fuel routing and flow separation edges
Implementation Method 2
Within the piston bowl, the fuel can be directed towards the piston's central axis, and the turbulence of this partial flow can be adjusted, particularly increased, within the bowl. Along the majority of the piston stages, multiple flow separation edges can be created to adjust the turbulence of the second partial flow as desired
Data Source
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AI summary
The invention relates to a piston (10) for an internal combustion engine, in particular an HPDI diesel-gas engine. The piston (10) has a piston bowl (12), in particular an omega-shaped piston bowl. The piston (10) has a piston crown surface (18) that is arranged in an annular shape around a central axis (M) of the piston (10). The piston has a plurality of piston stages (14, 16) that are arranged in an annular shape around the central axis (M) and are located between the piston crown surface (18) and the piston bowl (12). The piston geometry can lead to an increase in engine efficiency while simultaneously reducing exhaust emissions.