{{ post.title }}
글 편집
{{ post.author.name }}
Posted on
| Version | {{ post.target_version }} | Product |
{{ product.name }}
|
|---|---|---|---|
| Tutorial/Manual | {{ post.tutorial.upload_filename }} | Attached File | {{ post.file.upload_filename }} |
ㆍProduct: HEV and EV Transmission System
ㆍAnalysis Goal: Optimization of lubrication pathway to improve HEV and EV lubrication and cooling
Transmission oil plays two roles: lubricating the parts that are rotating at high speed in order to minimize wear, and responding to the heating phenomenon of each part as an appropriate coolant. But if the amount of oil is excessive, it becomes a resistance factor against each rotating part, which may have a negative effect on fuel efficiency. Therefore, oil path inside a transmission has been optimized, and the optimal amount of oil has been determined through visualization and quantification process of the model in order to get the best lubricating and cooling efficiency.
Process
① Configuration of dynamic model that includes rotation and other motions using the entire transmission model
② Co-simulation of the transmission oil model and the dynamic model
③ Benchmark test using an actual transmission (check for the quantitative behavior of oil)
④ Comparison between the actual test and analysis results, as well as detailed parameter tuning
⑤ Visual/numerical comparison and analysis of oil behavior effects according to the change of design parameters using the basic virtual model for which detailed parameter tuning has been completed
⑥ Analysis of the result according to various changes in driving conditions (acceleration, deceleration, and steering of a vehicle)
Key Technologies for Analysis
ㆍ Dynamic modeling of the internal parts of a transmission (RecurDyn Professional)
ㆍ Highly precise fluid modeling according to the characteristics of oil (Particleworks)
ㆍ Bi-directional exchange of essential physical quantity between high speed rotating parts and oil (Co-simulation)
ㆍHigh speed particle simulation technology through GPGPU (Particleworks GPU Solver)
ㆍ Calculation of pressure and speed between oil and the related parts with high accuracy
Images: Courtesy of Hyundai Motors (From the presentation of “Churning oil path optimization process development” by Chulmin Ahn at VDI Dritev 2018)
Toolkits
ㆍRecurDyn/Professional
ㆍRecurDyn/Gear
ㆍRecurDyn/Bearing
ㆍParticleworks Interface
The Problems that Customers are Facing
• Performance degradation of transmission caused by inefficient oil lubrication
• Demand for improved lubrication performance compared to the existing products
• Difficulty to evaluate the lubrication performance because of the invisibility of transmission inside
• Excessive time and cost to review various designs and operating conditions through prototypes
Solutions
Time and cost reduction through quantitative performance evaluation of various designs and operating conditions (load torque and oil level) by visualizing inside the transmission using both RecurDyn and Particleworks
Outcomes
ㆍOptimization of the oil path configuration that is required in the initial stage of transmission design through highly precise visualization and quantification of the oil flow inside the transmission
•The resistance (Drag) created by oil on each rotating part, which is consistent with the test result, can be estimated in advance. The optimal amount of transmission oil can be proposed based on such estimation.
Other Applications
◀ Analysis of changes in load torque according to the difference in temperature of lubricating oil
ㆍRelationship between viscosity and load torque according to the temperature of lubricating oil after turning off the engine input torque
ㆍAnalysis of difference in reduction of speed according to lubrication status between the states that have different temperatures (viscosity)
◀ Analysis of the reduction gear train which takes into consideration the viscosity of lubricating oil
ㆍVisualization of the lubricating oil spray which was not possible until now
ㆍThe effect of the gear output according to the load of oil viscosity can be designed to be closer to reality
◀ Behavior analysis of lubricating oil spray inside the differential gearbox
ㆍAnalysis of load torque when viscous fluid (lubricating oil) has been added to the differential gear train robot
