Advanced Natural Gas Reciprocating Engine: Parasitic Loss Control through Surface Modification

Farshid Sadeghi ; Chin-Pei Wang

关键词: CONFIGURATION;    DYNAMOMETERS;    ENGINES;    FIBER OPTICS;    FLUID FLOW;    FRICTION;    LASERS;    LINERS;    LUBRICANTS;    LUBRICATION;    MACHINING;    MODIFICATIONS;    NATURAL GAS;    PISTONS;    SHEAR;    TESTING;    THICKNESS;    VELOCITY;   

DOI  :  10.2172/974561
RP-ID  :  None
PID  :  OSTI ID: 974561
Others  :  TRN: US201008%%473

美国|英语

来源: SciTech Connect

【 摘 要 】

This report presents results of our investigation on parasitic loss control through surface modification in reciprocating engine. In order to achieve the objectives several experimental and corresponding analytical models were designed and developed to corroborate our results. Four different test rigs were designed and developed to simulate the contact between the piston ring and cylinder liner (PRCL) contact. The Reciprocating Piston Test Rig (RPTR) is a novel suspended liner test apparatus which can be used to accurately measure the friction force and side load at the piston-cylinder interface. A mixed lubrication model for the complete ring-pack and piston skirt was developed to correlate with the experimental measurements. Comparisons between the experimental and analytical results showed good agreement. The results revealed that in the reciprocating engines higher friction occur near TDC and BDC of the stroke due to the extremely low piston speed resulting in boundary lubrication. A Small Engine Dynamometer Test Rig was also designed and developed to enable testing of cylinder liner under motored and fired conditions. Results of this study provide a baseline from which to measure the effect of surface modifications. The Pin on Disk Test Rig (POD) was used in a flat-on-flat configuration to study the friction effect of CNC machining circular pockets and laser micro-dimples. The results show that large and shallow circular pockets resulted in significant friction reduction. Deep circular pockets did not provide much load support. The Reciprocating Liner Test Rig (RLTR) was designed to simplifying the contact at the PRCL interface. Accurate measurement of friction was obtained using 3-axis piezoelectric force transducer. Two fiber optic sensors were used to measure the film thickness precisely. The results show that the friction force is reduced through the use of modified surfaces. The Shear Driven Test Rig (SDTR) was designed to simulate the mechanism of the piston ring pass through the liner. Micro PIV system was provided to observing the flow of lubricant in the cavity (pocket). The Vorticity-Stream Function Code was developed to simulate the incompressible fluid flow in the rectangular cavity.