Twin-Volute Turbine Vane Layout for Exhaust Leakage Reduction
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Solution Overview
Problem
Existing turbocharger designs suffer from exhaust gas leakage between volutes, leading to reduced engine performance and efficiency due to increased pumping work required to overcome back pressure in non-pulsing volutes.
Innovation Solution
A turbine assembly with vanes that are positively clocked and overlapping with the tips of the tongues, directing exhaust gas flow more effectively into the desired volute, reducing leakage and increasing scroll separation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If exhaust gas flows through a pulsing volute, then engine power is improved, but exhaust gas leaks into the non-pulsing volute causing increased pumping work
Solution Approach 1:
The turbine housing is segmented into two separate volutes (first and second volutes) that are spatially divided to handle exhaust flows from different cylinder banks. Each volute is further segmented into a pulsing portion and a non-pulsing portion, creating distinct flow paths that prevent exhaust gas leakage between volutes while maintaining separate pulsing and non-pulsing regions within each volute.
Solution Approach 2:
Different portions of each volute are given different flow characteristics: the pulsing portion receives high-velocity pulsing exhaust flow to maximize turbine power, while the non-pulsing portion receives steady flow. The design locally optimizes each portion's geometry and flow path to achieve the desired flow quality without compromising the other.
2Loss of energy
If scroll separation is increased to reduce exhaust gas leakage, then pumping work is reduced, but device complexity increases
Solution Approach 1:
The design merges the functions of separation and flow direction into the volute housing structure itself. The dividing wall between volutes simultaneously achieves scroll separation to prevent exhaust leakage and integrates the pulsing and non-pulsing portions within each volute, eliminating the need for additional separate components.
Solution Approach 2:
The volute housing structure serves multiple functions: it separates exhaust flows from different cylinder banks, creates pulsing and non-pulsing flow paths, prevents exhaust gas leakage between volutes, and directs flow to the turbine wheel. This multi-functionality reduces the need for additional components and simplifies the overall device.
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 reduces exhaust gas leakage, minimizing pumping work and enhancing engine performance by improving scroll separation, thereby increasing overall engine efficiency.
Implementation Method 1
Vanes may interpose the outlets and a turbine wheel, so as to direct exhaust gas flow onto the turbine wheel
Data Source
Figure 1
Figure 2a~2b
Figure 2c~2e
AI summary
A turbine assembly for a turbocharger is disclosed. The turbine assembly comprises a housing and a vane assembly. The housing defines a flow path between an inlet and an outlet, the housing extending around an axis. The housing comprises first and second volutes which define a respective first and second flow passage. A circumferential outlet portion of each of the first and second volutes is defined by first and second tongues. The housing further comprises a first aperture in which a vane assembly is received. The vane assembly comprises a plurality of vanes circumferentially distributed about a turbine wheel-receiving bore, each of the plurality of vanes comprising a leading edge and a trailing edge. Each of the plurality of vanes has a fixed orientation. The plurality of vanes comprises a first vane and a second vane. The first vane is the vane having its leading edge disposed in closest proximity to a tip of the first tongue. The second vane is the vane having its leading edge disposed in closest proximity to a tip of the second tongue. For each of the first vane and the second vane, the leading edge at least partly overlaps the tip of the proximate tongue circumferentially.