Controlled Area Progression Diffuser for Compressor Surge Suppression
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Solution Overview
Problem
Turbocharger compressors exhibit undesirable choke or surge behavior at certain low mass flow rates and high pressure ratios, leading to flow instability and performance degradation.
Innovation Solution
Implementing a controlled area progression diffuser with varying diffuser width and annulus area progression to suppress airflow separation and instability, achieved by shaping the diffuser faces to control the airflow path and reduce separation bubbles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional diffuser with linearly increasing annulus area is used, then the compressor operates efficiently at high mass flow rates, but the compressor exhibits surge behavior and flow instability at low mass flow rates
Solution Approach 1:
The patent changes the geometric parameters of the diffuser by controlling the progression of annulus area along the radial direction. Specifically, the diffuser is designed so that the annulus area does not increase linearly but follows a controlled progression that prevents airflow separation and surge at low mass flow rates, thereby expanding the stable operating range to lower mass flow rates while maintaining reliability
Solution Approach 2:
The diffuser geometry is designed with dynamic characteristics that adapt to different operating conditions. The controlled area progression creates a diffuser configuration that dynamically responds to varying mass flow rates, preventing surge at low flows while maintaining efficiency across the operating range
2Reliability
If the diffuser width is increased to reduce airflow separation, then surge is suppressed, but the diffuser size and device complexity increase
Solution Approach 1:
Rather than simply increasing diffuser width, the patent changes the progression pattern of the annulus area along the radial direction. This parameter change achieves surge suppression through optimized area distribution that controls airflow attachment, avoiding the need for excessive diffuser width while reducing geometric complexity
Solution Approach 2:
The diffuser design applies local quality optimization by controlling the area progression in specific radial zones. The annulus area is designed to progress at different rates in different sections of the diffuser, creating locally optimized flow conditions that suppress surge without requiring uniform increases in diffuser dimensions throughout
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
Enhances compressor efficiency and expands the operating range to lower mass flow rates while reducing surging, improving performance and stability.
Implementation Method 1
a diffuser that slows down the expelled air to cause a pressure rise
Implementation Method 2
shaping the diffuser faces to control the airflow path and reduce separation bubbles
Data Source
AI summary
A controlled area progression diffuser for a compressor may be defined by a bearing diffuser face of a bearing housing and a compressor diffuser face of a compressor housing that are spaced apart by a diffuser width, and airflow from a compressor wheel enters the controlled area progression diffuser through a diffuser inlet, flows between the diffuser faces, and flows out of a diffuser outlet to a volute. The diffuser faces may be shaped so that the diffuser width decreases as the controlled area progression diffuser extends radially away from the compressor wheel toward the volute so that an annulus area of the controlled area progression diffuser does not increase linearly for at least a portion of a radial length of the controlled area progression diffuser.