NNW-TopViz流场可视分析系统

流场可视化技术采用图形图像直观地表现CFD数值模拟的计算结果，使用户能够方便地对这些数据进行分析、比较和研究。然而，CFD数值模拟的流动复杂，其产生的流场数据规模巨大、数据类型复杂、特征提取困难，传统的串行可视化软件效率低、交互手段单一，难以满足数据分析的需求。国家数值风洞（NNW）工程研制了一套流场数据处理可视化软件系统（NNW-TopViz，简称TopViz），具有对流场数据处理与特征提取、几何图形绘制等可视化与交互功能。根据可视分析效率需求，TopViz实现了线程并行，在多核计算环境下有效提高了可视化计算和交互效率；针对流场特征提取困难、常规方法效率低的问题，TopViz实现了基于卷积神经网络的流场旋涡特征提取方法，提升了特征提取准确率和效率；为提高软件交互效率并提供便捷的交互方式和体验，基于头戴式显示设备和体感控制器构建沉浸式虚拟显示与交互平台，TopViz实现了手势和眼球凝视2种交互方法，提供沉浸式环境下多视图、多角度流场探测方式。

NNW-TopViz visualization analysis system for flow field

The flow field visualization technology visually displays the abstract calculation results of CFD numerical simulation in the form of graphic images, enabling users to easily analyze, compare, and study the results.However, the complex flow of CFD numerical simulation, huge generated data and complex data type make it difficult to conduct feature extraction, and thus difficult to achieve efficient visualization. The National Numerical Windtunnel (NNW) Project develops a field visualization software system, NNW-TopViz (TopViz for short), which has the function of field data processing, feature extraction, geometric drawing and human interaction. According to the efficiency requirements, TopViz deploys thread level parallelism to enhance the visualization computing. Due to the difficulties in flow field feature extraction and the low efficiency of conventional methods, TopViz implements the convolutional neural network-based flow field vortex feature extraction method, which improves the accuracy and efficiency of feature extraction. In order to improve software interaction efficiency and provide convenient interaction mode and experience, an immersive virtual display and interaction platform is built based on head-mounted display device and motion-sensing controller. TopViz realizes two interaction methods, namely gesture and eye gaze, and provides a multi-view and multi-angle flow field detection method in an immersive environment.