Reversible axial flow fans are used as emergency ventilation fans to discharge the smoke generated on the probable fires occurring in the underground transportation systems and mines as quickly as possible, without causing any harm to people exposed to it. The fans which are placed in different configurations according to the location of fire must be able to work bi-directionally, namely reversible. Due to this fact, the blade profiles of the fan must possess the same aerodynamic performance while working on either discharge or suction condition of the fan, dictated by direction of the rotation. This manuscript consists of the computation of the aerodynamic performances of symmetrical blade profiles of fully reversible axial fans by computational fluid mechanics (CFD) methods, developing a methodology for the design of reversible axial fans and analysis of the designed fan with CFD methods. The aerodynamic performances of the blade cascades are evaluated using FLUENT 6.0 software for different Reynolds numbers, solidities and angle of attacks of the cascade. The results of these computations are embedded into the developed methodology. Performance analysis of the reversible axial flow fan, which is designed with the developed methodology, is done with CFD techniques.

Axial Flow Fans: Design and Practice focuses on the design of axial flow fans and the practices involved in their applications. The manuscript first offers information on the fluid mechanics of ducted fans, boundary layer and skin friction relations, and aerofoil data for blade design. Discussions focus on flow deflection in cascade of aerofoils, pitching moment, lift, surface roughness in turbulent boundary layers, turbulent boundary layers in pressure gradients, laminar skin friction, viscosity and boundary layers, and similarity and non-dimensional numbers. The text then ponders on vortex flows in ducting and fan, ducts, and introduction to fan design methods. The book takes a look at the momentum and blade element considerations on free vortex flow of rotor and rotor losses. Topics include momentum considerations, profile drag, tip clearance losses, optimum conditions in terms of the flow and swirl coefficients, pressure relations and velocity vectors, and thrust and torque gradients. Tail fairing design and associated losses, overall efficiencies, torque, thrust, and power, and the design of fan unit with arbitrary vortex flow are also discussed. The publication is a dependable source of information for engineers and readers interested in the design of axial flow fans and practices involved in their operation.

Covers the theory, design, analysis, testing, and research of axial flow fans. Contains up-to-date data on recent developments in the field. Interrelates fan and duct design techniques. Discusses commercial and product development test procedures. Covers future experimental research objectives. Includes a reference section on F-series of airfoils.