本文考虑了用于车辆隧道通风系统的变螺距轴流风机。风扇的设计源自德国，被认为代表了“最先进的水平”，在20多年的运行经验中已经成熟。在美国，将其用于隧道通风系统似乎是合理的。介绍了该设计及其性能。三大领域——节能、空间要求和设备数量——提供了最大的节约潜力，并使这种风扇设计最具吸引力。引文:研讨会，ASHRAE交易，第86卷，第2部分，科罗拉多州丹佛

This paper considers variable pitch axial flow fans for application in Vehicular Tunnel Ventilating systems. The fan design is of German origin where it is considered to represent the "state of the art", matured over more than two decades of operating experience. Its utilization for tunnel ventilating systems in the U.S.A. appears to be justifiable. The design and its performance are described. Three major areas--energy conservation, space requirements and number of pieces of equipment, provide the largest savings potential and make this fan design most attractive.