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This article presents a method for improving electric motor noise and vibration analysis based on rotor load. The method first obtains two key parameters, namely the characteristics of the stator and rotor core material and the connection stiffness between the rotor skewed poles, through modal testing and simulation calibration of the stator and rotor. Subsequently, the electromagnetic simulation is used to calculate the torque fluctuation of each segment of the rotor skewed poles, which is used as input load for the structural simulation. The vibration of the suspension point and the radiation noise of the transmission housing are then calculated under the action of torque fluctuation. The study highlights the significant contribution of the rotor torsional mode to noise and vibration.

RDE test has been introduced to the light-duty vehicle certification process in both China 6 and Euro 6d standards. The RDE test shall be performed on-road with PEMS, which is developed to complement the current laboratory certification of vehicles and ensure cars to deliver low emissions under more realistic on-road driving conditions. Particulate matter has been highly perceived as a significant contributor to human health risks and thus strictly regulated globally. For the RDE evaluation, the MAW method used by the China 6 standard is usually found less stringent than the RMA method used by the Euro 6d standard. In the present study, both of the MAW and RMA methods were applied to different driving cycles and operating conditions, which met the general RDE test requirements, yet resulted in different evaluated PN results.

With upcoming China 6b emission regulation set for full implementation in July 2023, significant efforts are being made within China OEMs to meet the stringent gaseous emission requirements, which reduce gaseous emission limits by 29 to 50% from China 6a for NOx, THC, and CO over the worldwide harmonized light-duty test cycle (WLTC). With current engine and aftertreatment technology, cold-start emissions generated in the first 200 seconds of the WLTC typically makes up most of the total tailpipe emissions result, thus the reduction of cold-start emissions becomes vital to meet regulation requirements. Besides further improvement on engine technology with optimized calibration, a common method to improve cold-start performance is to add more platinum group metals (PGM) into three-way catalyst (TWC). An alternative approach to improve cold-start performance involves using a low mass substrate to enable faster heat up of the TWC.

As the China 6 light duty vehicle emission regulation is being implemented, PN becomes a challenge for vehicle type-approval emission tests. WLTC has replaced NEDC as the Type-I test cycle on the chassis dynamometer with more dynamic driving events. In addition, on-road RDE test is a challenge to calibrate the engine to meet tailpipe PN emissions because of the nature of the on-road conditions, i.e. varying ambient temperature, driving dynamics, altitude, etc. In response to China 6 requirements, GPF technology has been introduced. In this study, we pulled four China 6 compliant gasoline vehicles for the PN emission survey. The selected vehicles covered typical engine technologies including GDI/MPI with natural aspiration/turbo charger, representing the state of the art of the local engine capability. On one hand, it helps to build insight into the status of China 6 engine emission control technology through WLTC and RTS95 tests.

To meet the request of China National 6b emission regulations which will be officially implemented in China, firstly including the RDE emission test limits, the transient emissions on real road condition are paid more attention. A non-plug-in hybrid light-duty gasoline vehicles (HEV) sold in the Chinese market was selected to study real road emissions employed fast response NOx analyzer from Cambustion Ltd. with a sampling frequency of 100Hz, which can measure the missing NO peaks by standard RDE gas analyzer now. Emissions from PEMS were also recorded and compared with the results from fast response NOx analyzer. The concentration of NOx emissions before and after the Three Way Catalyst (TWC) of the hybrid vehicle were also sampled and analyzed, and the working efficiency of the TWC in real road driving process was investigated.

This paper focuses on dynamic analysis and frame optimization of a FSAE racing car frame. Firstly, a Multi-Body Dynamic (MBD) model of the racing car is established using ADAMS/Car. The forces and torques of the mechanical joints between the frame and suspensions are calculated in various extreme working conditions. Secondly, the strength, stiffness and free vibration modes of the frame are analyzed using Finite Element Analysis (FEA). The extracted forces and torques in the first step are used as boundary conditions in FEA. The FEA results suggest that the size of the frame may be not reasonable. Thirdly, the size of the frame is optimized to achieve minimized weight. Meanwhile the strength and stiffness of the frame are constrained. The optimization results reveal that the optimization methodology is powerful in lightweight design of the frame.

A novel combustion system called Jet Controlled Compression Ignition (JCCI) is investigated to directly control the combustion phasing of premixed diesel compression ignition. Experiments were conducted on a single-cylinder naturally aspirated diesel engine at 3000r/min without EGR. The experimental results showed a good linear relationship between spark timing in the ignition chamber and CA10 and CA50, which indicated the ability for direct combustion phasing control in premixed diesel combustion. The NOx and soot emissions gradually changed with the spark advance angle. Then, load sweep experiments were performed with fixed spark timing. The results showed the onset of combustion was almost unchanged over a wide load range. Additionally, NOx emission was greatly reduced at all test loads compared with the original engine. Soot emission was reduced at a comparatively high load while similar with that of the original engine at low loads.

With ever-increasing oil and gasoline prices, automotive manufacturers are striving to improve fuel economy. There are many factors that affect vehicle fuel consumption, such as engine size, vehicle weight, driving habits, and more. For a particular vehicle, engine combustion quality is one of the most important factors that affect fuel economy. Engine combustion quality also directly affects engine emissions, vehicle drivability, and vehicle NVH. Automotive manufacturers have been using different technologies to control engine combustion quality, such as using low cost pressure transducers to measure and control engine combustion in real time. In this paper, the authors have proposed a method that could directly use the Crank Position Sensor (CPS) signal to measure engine combustion quality.