增压器蜗壳喷嘴出口的变宽度设计思想和计算

A Variable Width Design of Nozzle Outlet in a Turbocharger Scroll

为了研究涡轮增压器无叶蜗壳喷嘴宽度对其出口气流速度场分布的影响 ,用 k-ε双方程模型模拟蜗壳内的气流运动情况 ,计算了不同喷嘴宽度对无叶蜗壳喷嘴出口气流角和速度分布的影响。计算中发现固定喷嘴宽度难以解决气流角和速度分布不均匀的问题 ,因而提出了一种变喷嘴宽度的设计思想。计算结果表明 ,变喷嘴宽度能明显改善气流角和速度分布的均匀性。

In order to investigate the influence of nozzle width on the velocity distribution at the nozzle outlet of a vaneless scroll, the numerical simulation of a three-dimensional turbulent flow field inside a turbocharger scroll was described and the k - ε two-equation model was used to simulate the flow in the scroll. The flow angle and velocity distributions at the scroll nozzle outlet with different widths were calculated. The results show that it is difficult for the flow angle and velocity distribution to be uniform along the circumferential direction with fixed nozzle width. In this paper, a variable nozzle width design idea was presented. The calculating results show that the distributions of the flow angle and the velocity at the nozzle outlet with the variable width are more uniform than that with fixed width.