Industrial machineries, such as construction machinery which mounts a diesel engine, are noisier than passenger cars, and these noises affect a physical burden not only for neighboring residents but also for workers.&nbsp; As the characteristics of these noises generated by construction machinery, the cooling system noise which is generated when a heat exchanger such as a radiator is forced convection cooled by an axial flow fan has a great influence on the overall noise level.&nbsp; In order to reduce the cooling system noises, it is necessary to improve the efficiency of the cooling system, that is, the energy consumption must be saved while the cooling performance is maintained.&nbsp; One of the solutions is to generate required cooling air flow rate with a low fan speed.&nbsp;There are two kinds of approaches to realize it.&nbsp; First, it is to improve the P-Q characteristic of the cooling fan.&nbsp; There are many reports regarding the improvement of P-Q characteristic.&nbsp; As the result, it is clarified that P-Q characteristic is affected by the structure of the fan and obstacles which are placed upstream side or downstream side.&nbsp; Kawaguchi et al. investigated the effect of obstacle on air flow rate and experimentally clarified that the degree of the effect of obstacles which affects P-Q characteristic varies depending on the air flow rate range.&nbsp;Next approach is to reduce the pressure drop in the ventilation path through which the flow generated by the cooling fan, but it is difficult to predict and estimate the three-dimensional pressure drop characteristic in advance.&nbsp; Therefore, in general, the pressure drop characteristic of the entire system is estimated with the coefficient which is multiplied the pressure drop characteristic of the radiator which is contained in the ventilation path, and the accuracy depends on the amount of experience of the manufacturer.&nbsp; However, if there is a major change regarding the shape or layout in the system, the cooling air flow rate will be generated less than expected, and the cooling system may need to be re-designed.&nbsp;A computational approach (CFD) is effective for estimating the three-dimensional pressure drop characteristic of a system, but there are few reports which clarify the mechanism of the generation of the loss and suggest the pressure drop reduction from the viewpoint of the flow field.&nbsp;In this study, the authors investigate the pressure drop mechanisms generated by the electric cooling enclosure of the construction machinery.&nbsp; In particular, the three-dimensional flow field around the electric cooling fan is visualized by the numerical simulation using ANSYS-CFX17.0 and the details of pressure drop mechanisms in this system will be investigated.

Pressure Drop Mechanisms Generated in a Cooling System Enclosure of Construction Machinery

Paper Proceedings: https://asmedigitalcollection.asme.org/FEDSM/FEDSM2021/volume/85284

ASME 2021 Fluids Engineering Division Summer Meeting (FEDSM2021)

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