An Investigation of Integrated System Dynamic Simulation for Reciprocating Machinery, 03-9201

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Principal Investigators
Fernand A. Thomassy
John P. Harrell
Gregory N. Wattis

Inclusive Dates: 07/01/01 - 01/01/02

Background - Complex mechanical system simulation is continuously being refined. Demand for more comprehensive and accurate simulation has increased as manufacturers struggle to improve the predictability and reliability of their designs. In addition, the resolution of machinery problems requires solutions that correctly characterize the complex behavior of mechanical systems with multiple components and dependent interactions. This project developed and verified a simulation methodology to achieve this level of fidelity through the evaluation of the Clark HBA-6 engine/compressor, a known system that represents a class of machine that could benefit from this technology.

Approach - An incremental approach was used to apply this modeling methodology. First, a baseline model of the Clark HBA-6 engine was evaluated through baseline simulation methods that solve each component or subassembly separately. Next, system components were added one at a time to increase fidelity of the simulation. Results from each simulation were compared to demonstrate the significance of each integrated subsystem in achieving an accurate result. This project demonstrated an integrated approach to cranktrain simulation that successfully combines analytical methods that have traditionally had separate foci.

Accomplishments - The investigators successfully integrated flexible components, nonlinear dynamics, and dynamically loaded lubrication technologies into a comprehensive system solution that demonstrated this technology. It was shown that it is critical to combine the effects of crankshaft and bearing mount flexibility. Integration of the hydrodynamic bearing models is not critical to modeling major characteristics in the dynamic system; but behavior could be very important in the simulation in the evaluation of critical design margins.

Effects of integration on crankshaft stress

Integrated model of the Clark HBA-6 engine/compressor

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