Search Results (3)

This study performed a 3D CFD analysis on a GP3 rotary engine to determine the stroke and flow characteristics and examine the thermal- and flow-related design factors’ validity. The 3D CFD analysis was performed using the CONVERGE program, utilizing the automatic grid generation function based on the 3D engine design drawing, which is suitable for a rotating rotary engine geometry. The target species and error tolerance were selected based on the GRI-Mech 3.0 full reaction mechanism to validate the reaction model and define a reasonable range of target species and error tolerances. The RNG k-ε turbulence and SAGE combustion models were also employed to analyze the four-stroke characteristics for the GP3 engine by visualizing the internal flow. The various outcomes confirmed the rotary engine’s unique characteristics and were reasonably interpreted to validate the engine design factors. In particular, the EGR phenomenon in the intake and exhaust port overlap area and the interference phenomenon in the port overlap area between adjacent cylinders are unique to the engine, and were rationally analyzed to more accurately predict the engine’s performance. The results of this study regarding the flame quenching regions indicated power and efficiency, and the emission characteristics can be used to validate the design parameters. Full article

The objective of this study is to develop a 1D CFD simulation model to identify the optimal design parameters, using GT-POWER prior to the optimization of a new rotary engine derived from a three-lobe gerotor pump (GP3 RTE) based on 3D CFD simulation. The models were compared based on their respective development stages (steps 1–4) to ascertain the impact of each parameter on performance. The step 4 model, which exhibited a similar trend to that observed in the 3D CFD results, was selected for further analysis and validation. The developed model accurately predicted GP3 RTE performance in terms of fuel consumption, indicated power, efficiency, and exhaust gas reticulation (EGR) behavior, approaching the accuracy of the CONVERGE model. Furthermore, the optimal intake/exhaust port locations and operating conditions of the GP3 RTE were derived using the developed step 4 model. The model provided a convenient and powerful tool for obtaining basic information regarding the unique behavior of the GP3 RTE, thereby enabling the optimization of the design parameters without the necessity for time-consuming three-dimensional design modifications. Full article

The objective of this study was to analyze the effect of tillage type (i.e., primary and secondary tillage) and gear selection (P1L2 to P1L4) on the working load of tractor–implement systems during rotary tillage. Soil properties change with depth, and differences in properties along the depth distribution, such as the location of formation of the hardpan layer, internal friction angle, and moisture content, affect the load of rotary tillage operations. Therefore, the physical properties of soil along the field depth distribution were measured to analyze the effect of tillage type and gear selection on workload in rotary tillage. In addition, a load measurement system equipped with PTO torque meter, axle torque meter, proximity sensor, and RTK-GPS were configured on the 42 kW agricultural tractor. The experimental results show that the combination of tillage type and gear selection has a wide-ranging effect on the tractor’s workload and performance when the rotavator operated at the same tilling depth. Overall working load was higher by up to 14% (engine) and 29.1% (PTO shaft) in primary tillage compared to secondary tillage when the gear selection was the same. When the tillage type is the same, it was analyzed that the overall average torque increased by up to 35.9% (engine) and 33.9% (PTO shaft) in P1L4 compared to P1L2 according to gear selection. Based on load analysis results, it was found that the effect of gear selection (Engine: 4–14%, PTO: 12.1–28.6%) on engine and PTO loads was higher than that of tillage type (Engine: 31.6–35.1%, PTO: 31.9–32.8%), and the power requirement tended to decrease in secondary tillage. Therefore, working load should be considered according to the soil environment and tillage type when designing agricultural machinery system. Full article