• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.2
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• pp.101-108
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• 2004

Recently, a semi-active shock absorber has been taking interest because of its low cost and simple structure than the active one. CFD analysis has been conducted to investigate the continuous and variable damping characteristics of the semi-active shock absorber. Also, the flow resistance characteristics of a spool valve has been examined to identify individual parameters(namely, exponent and discharge coefficient) of pressure-flow rate relation needed for the accurate valve modeling. The flow field in the damping valve was simulated using the commercial code, CFX-5.3. The numerical results showed reasonable agreement with the experimental outputs. The pressure distribution with the variation of spool opening length and volume flow rate were discussed in detail. And the continuous and variable damping performance was found clearly. The individual parameters of spool valve were obtained as a function of orifice area. The exponent and discharge coefficient were fitted in with the first and the third polynomial respectively.

• Transactions of the Korean Society of Automotive Engineers
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• v.19 no.2
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• pp.57-65
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• 2011

In this paper, a hydropneumatic modeling and dynamic analysis of a heavy truck semi-active cabin air suspension system is presented. Semi-active cabin air suspension system improves driver's ride comfort by controlling the damping characteristics in accordance with driving situation. So it can reduce vibration between truck frame and cabin. Semi-active cabin air suspension system is consist of air spring, leveling valve and CDC shock absorber, and full cabin system are mathematically modelled using AMESim software. Simulation results of components and full cabin system are compared with experimental data of components and test results of a cabin using 6 axis simulation table. It is found that the simulation results are in good agreements with test results, and the hydropneumatic model can be used well to predict dynamic characterics of heavy truck semi-active cabin air suspension system.