Assembly for silencing engine cooling fan noise

The aerodynamic inefficiencies of motor vehicle cooling systems are generally of secondary importance to their production costs. However, the advent of the inexpensive moulded fan has meant that an improvement in cooling system aerodynamics can be more readily achieved which could reduce costs and radiator sizes, with the additional benefits of predictable performance and improved economy. In the investigation described, the design objective was to meet the top gear cooling targets entirely with ram-induced airflow, and to design the engine driven fan so that it consumed negligible power for top gear conditions, whilst being capable of meeting the cooling targets in the intermediate gear ratios. The work divided itself into the following three sections: (1) The prediction and achievement of the maximum ram-induced airflows. (2) Designing the cooling fan to be effectively free-wheeling and, therefore, consuming negligible power during top gear motoring, and to measure the performance of the resulting fan throughout the ram and fan assisted airflow regimes. (3) Designing and predicting the performance of a cooling system which was subsequently built and installed in a test vehicle in order to check its performance and making an overall comparison with regard to the original system. The paper shows that the design objectives were closely achieved. The 1·7 litre test vehicle was cooled satisfactorily with a one foot square radiator with the expenditure of only 0·9 hp in the cooling system when travelling at 70 mile/h.

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Two-step computational aeroacoustics approach for underhood cooling fan application

INTER-NOISE and NOISE-CON Congress and Conference Proceedings ◽

10.3397/in-2021-2467 ◽

2021 ◽

Vol 263 (3) ◽

pp. 3615-3624

Author(s):

Parag Chaudhari ◽

Jose Magalhaes ◽

Aparna Salunkhe

Keyword(s):

Flow Field ◽

Sound Pressure ◽

Acoustic Analysis ◽

Air Flow ◽

Computational Aeroacoustics ◽

Noise Sources ◽

Fan Noise ◽

Cooling Fan ◽

Sound Pressure Levels ◽

One Step

Aeroacoustic noise is one of the important characteristics of the fan design. Computational Aeroacoustics (CAA) can provide better design options without relying on physical prototypes and reduce the development time and cost. There are two ways of performing CAA analysis; one-step and two-step approach. In one-step CAA, air flow and acoustic analysis are carried out in a single software. In two-step approach, air flow and acoustic analysis are carried out in separate software. Two-step CAA approach can expedite the calculation process and can be implemented in larger and complex domain problems. For the work presented in this paper, a mockup of an underhood cooling fan was designed. The sound pressure levels were measured for different installation configurations. The sound pressure level for one of the configurations was calculated with two-step approach and compared with test data. The compressible fluid flow field was first computed in a commercially available computational fluid dynamics software. This flow field was imported in a separate software where fan noise sources were computed and further used to predict the sound pressure levels at various microphone locations. The results show an excellent correlation between test and simulation for both tonal and broadband components of the fan noise.

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Study of Influence of MRF Method on the Prediction of the Engine Cooling Fan Performance

10.4271/2011-01-0648 ◽

2011 ◽

Cited By ~ 3

Author(s):

Yuji Kobayashi ◽

Itsuhei Kohri ◽

Yukio Matsushima

Keyword(s):

Fan Performance ◽

Engine Cooling ◽

Cooling Fan

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