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Excellence in Research: Co-axial Flow Mixing and Control using Ultra-High Frequency Actuators

卓越的研究：使用超高频执行器的同轴流混合和控制

基本信息

批准号：
1900177
负责人：
John Solomon
金额：
$ 50万
依托单位：
Tuskegee University
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2019
资助国家：
美国
起止时间：
2019-08-01 至 2024-07-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1900177&HistoricalAwards=false
关键词：
Excellence Research Co axial Flow

项目摘要

Innovative fuel-air mixing technologies are essential to the continual advancement of faster and more reliable aircrafts for both national defense and air transportation. This project will focus on a novel fuel injection scheme to enhance and control mixing of a fluid (fuel) with a fast moving air. The proposed scheme consists of two co-axial nozzles: a central nozzle surrounded by an annular one, through which air and fluid are injected simultaneously. While the fluid is supplied through the annular nozzle in a steady stream, the central nozzle injects air in a pulsed manner to enhance mixing. The innovative concept for the proposed injection system is in its ability to pulse the central air jet at very high frequencies (20,000-30,000 pulses per second). It is anticipated that the fluid (fuel) and the high frequency pulsed air will be mixed more effectively in this manner. To investigate this, an experimental fluid mechanics research lab will be equipped with new capabilities utilizing the state-of-the-art, advanced laser-based flow diagnostics that are required for this study. The project will also use educational plans that have been developed based upon established learning theories to provide more effective research experience to underrepresented students in engineering.Major goals of this project include design, development, and characterization through fundamental studies of an active co-flow injection system for enhanced fuel-air mixing at high speeds. The proposed system consists of a supersonic actuation air jet at the inner core that provides large mean and fluctuating velocity profiles in the shear layer of a steadily-injected annular fluid, where the fluctuations occur at a designated and controllable ultra-high frequency. It is expected that the mixing of air with the co-flowing fluid can be improved and controlled using resulting stream-wise vortices that are tailored to the mean flow in this manner. The specific tasks include quantitative characterization of mixing through measurement of seed particle density distribution using planar laser-induced florescence (PLIF) and velocity and vorticity field measurement using particle image velocimetry (PIV). Using these data, the diffusive mixing characteristics of the system (e.g., the timescales of evolution, interfacial area generation and mixing efficiency) will be studied and correlated to the relevant non-dimensional parameters involved. Specific educational activities include targeted infusion of advanced topics useful in research to an undergraduate level fluid mechanics course which provides additional support, and access to students whose pre-college situations may otherwise preclude success in engineering research.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

创新的油气混合技术对于国防和航空运输领域更快、更可靠的飞机的持续发展至关重要。该项目将集中在一个新的燃料喷射方案，以加强和控制流体（燃料）与快速移动的空气的混合。所提出的方案包括两个同轴喷嘴：一个中心喷嘴周围的环形，通过它的空气和流体同时注入。当流体以稳定流通过环形喷嘴供应时，中心喷嘴以脉冲方式喷射空气以增强混合。所提出的喷射系统的创新概念在于其能够以非常高的频率（每秒20，000 - 30，000个脉冲）对中心空气射流施加脉冲。可以预期，流体（燃料）和高频脉冲空气将以这种方式更有效地混合。为了调查这一点，实验流体力学研究实验室将配备新的能力，利用本研究所需的最先进的，先进的基于激光的流动诊断。该项目还将使用基于已建立的学习理论开发的教育计划，为工程领域代表性不足的学生提供更有效的研究经验。该项目的主要目标包括设计、开发和表征，通过对高速下增强燃料-空气混合的主动共流喷射系统的基础研究。所提出的系统包括一个超音速驱动的空气射流在内核，提供大的平均值和波动的速度分布在剪切层中的一个快速注入的环形流体，其中的波动发生在一个指定的和可控的超高频。可以预期的是，空气与同向流动流体的混合可以使用由此产生的流向涡流来改善和控制，该流向涡流以这种方式被定制为平均流。具体的任务包括通过使用平面激光诱导荧光（PLIF）测量种子颗粒密度分布和使用粒子图像测速（PIV）的速度和涡量场测量混合的定量表征。使用这些数据，系统的扩散混合特性（例如，演化的时间尺度、界面面积产生和混合效率）将被研究并与所涉及的相关无量纲参数相关联。具体的教育活动包括有针对性的注入先进的主题研究有用的本科水平的流体力学课程，提供额外的支持，并获得学生的大学前的情况可能会妨碍成功的工程研究。这个奖项反映了NSF的法定使命，并已被认为是值得通过评估使用基金会的智力价值和更广泛的影响审查标准的支持。