Ported Shroud Compressor Housing Noise Reduction
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Solution Overview
Problem
Turbochargers with standard ported shroud compressor housings experience aero-acoustic noises due to interaction between the compressor nut and imbalance correction region, leading to first-order pulsation noise and blade pass frequency errors, which affect NVH and rotor stability.
Innovation Solution
A turbocharger design featuring a ported shroud compressor housing with a volute base, inducer ring, and recirculation cavity, along with a compressor nut having an imbalance correction region, which includes specific geometry features such as diameter transitions and angled recirculation slots to reduce aero-acoustic noise and improve airflow stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If a standard compressor nut with imbalance correction region is used, then rotor imbalance is corrected, but aero-acoustic noise and first order pulsation noise are generated due to interaction with the ported shroud compressor housing
Solution Approach 1:
The harmful interaction between the compressor nut imbalance correction region and the ported shroud compressor housing is eliminated by removing the imbalance correction region from the compressor nut design, thereby eliminating the source of aero-acoustic noise while maintaining rotor stability through alternative means
Solution Approach 2:
A ported shroud compressor housing with specifically designed inlet geometry acts as an intermediary that reduces sensitivity to first order pulsation noise and blade pass frequency errors, decoupling the noise generation mechanism from the rotor balance function
2Stability of the object's composition
If a ported shroud compressor housing is used, then speed line stability and map width are enhanced, but first order pulsation noise is generated due to interaction with the compressor nut
Solution Approach 1:
The inlet geometry of the ported shroud compressor housing is locally optimized with specific contour shapes and diameter transitions that reduce sensitivity to first order pulsation noise while maintaining the overall speed line stability benefits of the ported shroud design
Solution Approach 2:
The ported shroud compressor housing inlet geometry employs asymmetric contour designs that are specifically tailored to reduce sensitivity to blade pass frequency errors and first order pulsation noise, breaking the symmetry that would otherwise amplify these noise components
3Volume of moving object
If the ported shroud compressor housing inlet diameter is smaller than the compressor inducer diameter, then compactness is achieved, but aero-acoustic noise sensitivity increases
Solution Approach 1:
The inlet geometry transitions from a simple circular cross-section to a three-dimensional contoured shape with varying cross-sectional areas along the flow path, utilizing dimensional complexity to reduce noise sensitivity while maintaining compact overall dimensions
Solution Approach 2:
The inlet geometry parameters including contour curvature, diameter transitions, and cross-sectional area distribution are optimized to reduce sensitivity to first order pulsation noise and blade pass frequency errors, allowing compact design without sacrificing aero-acoustic performance
Data Source
AI summary
A turbocharger includes ported shroud compressor housing disposed about a compressor wheel, having an air inlet passage extending axially along and circumferentially about a longitudinal axis, volute base portion operably adjacent to compressor wheel, contour that encircles and complementarily matches compressor wheel, inducer including ring and plurality of extending members, inlet section extending from volute base portion, and recirculation cavity formed in volute base portion and inlet section with a recirculation slot and inlet slot for reentry of airflow into inlet section. The ring has an inner wall surface defining a first section extending axially along the longitudinal axis and proximate to the compressor wheel, second section extending from first section radially away from longitudinal axis, and third section extending from second section along longitudinal axis and distal to the compressor wheel. The inlet section has a first diameter and third section has a second diameter greater than first diameter.