Analysis of Cracking Reason and Optimization Design of the Heat Shield for an Automobile Exhaust Pipe

2022 ◽  
pp. 423-433
Author(s):  
Pengfei Dai ◽  
Tianwen Li ◽  
Xiaodong Chen ◽  
Xiaotao Zhang ◽  
Chong Wang ◽  
...  
Keyword(s):  
Optimization Design ◽  
Heat Shield ◽  
Exhaust Pipe ◽  
Automobile Exhaust

scholarly journals Research on Optimization Design of SCR Nozzle for National VI Heavy Duty Diesel Engine

Catalysts ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 452 ◽  
Author(s):  
Feng Qian ◽  
Dong Ma ◽  
Neng Zhu ◽  
Peng Li ◽  
Xiaowei Xu
Keyword(s):  
Diesel Engine ◽  
Conversion Efficiency ◽  
Optimization Design ◽  
Exhaust Pipe ◽  
Heavy Duty ◽  
Deposit Formation ◽  
Nox Conversion ◽  
Heavy Duty Diesel ◽  
Scr System ◽  
Nox Conversion Efficiency

For the National VI heavy-duty diesel vehicles, NOx emission regulations are becoming more and more stringent, and the selective catalytic reduction (SCR) system has become a necessary device. The design of the adblue nozzle in the SCR system is especially critical, directly affecting the NOx conversion efficiency and deposit formation. According to the structure of a National VI diesel engine exhaust pipe and SCR system, the nozzle is optimized by computational fluid dynamics (CFD) method to avoid the collision between the urea droplets and the exhaust pipe wall, to ensure that the exhaust gas and the urea droplets are as much as possible in full contact to ensure a sufficient urea pyrolysis. With the optimized nozzle, the NH3 distribution uniformity of the inlet face of the SCR catalyst can increase from 0.58 to 0.92. Additionally, test verifications are implemented based on the spray particle size test and the engine bench tests; the results show that the Sauter mean diameter of the optimized nozzle is more decreased than the initial nozzle and that the NOx conversion efficiency of the World Harmonized Transient Cycle (WHTC) and World Harmonized Stationary Cycle (WHSC) cycle improves by nearly 3%; additionally, it can also avoid deposit formation.

The Structure Design and Exhaust Mechanism on Hybrid Supercharger

2013 ◽  
Vol 419 ◽  
pp. 209-216
Author(s):  
Hua Pan Xiao ◽  
Zi Fan Fang ◽  
Jing Fang ◽  
Hui Li ◽  
Kong De He ◽  
...  
Keyword(s):  
Design Theory ◽  
Optimization Design ◽  
Research Result ◽  
Branch Pipe ◽  
Flow Distribution ◽  
Structure Design ◽  
Exhaust Pipe ◽  
Pressure Pipe ◽  
Connection Type ◽  
Parameter Optimization Design

Aiming at solving the problem of underwater exhaust for underwater vehicle, a new underwater exhaust scheme is presented with structure and power supercharger, which the structure design is analyzed and studied. Firstly, the fluid characteristic is analyzed in junction between the exhaust pipe of diesel and the pressure pipe of air compressor. The connection type of them is presented and the exhaust mechanism is proved that low pressure gas can exhaust out from exhaust pipe by entrainment. Subsequently, based on the Bernoulli principle, the flow distribution is analyzed in the branch pipe. Finally, taking exhaust performance as optimum target, the parameter optimization design is carried out for branch pipe by using DOE; the optimal structure size is also obtained for exhaust pipe by regression analysis. The research result predicts that a new underwater exhaust scheme and its design theory are presented in this paper.

Numerical Computation of Temperature in APU Compartment of Passenger Plane

2012 ◽  
Vol 220-223 ◽  
pp. 855-858
Author(s):  
Rang Shu Xu ◽  
Nana Zhang ◽  
Ling Niu ◽  
Meng Yang
Keyword(s):  
Heat Transfer ◽  
Numerical Computation ◽  
Transfer Process ◽  
Optimization Design ◽  
Radiation Heat Transfer ◽  
Heat Transfer Process ◽  
Exhaust Pipe ◽  
Radiation Heat ◽  
Flow Information ◽  
Cooling Air

In order to study heat transfer process in APU compartment of passenger plane and to perform structure thermal analysis, temperature field of APU compartment has been calculated by numerical computation. The computation model of flow and heat transfer process in APU compartment are setup by commercial CFD software Fluent, Realizable k-ε turbulent model and S2S thermal radiation model are used, and the flow field, temperature and heat flow information are acquired. Radiation heat transfer is the major heat transfer process in APU compartment; APU fireproofing cover and heat insulation hood of exhaust pipe function work as radiation heat shielding screens; and cooling air in the APU fireproofing cover plays an important part in decreasing the temperature of the fireproofing cover; the injection cooling air in the exhaust pipe reduced the wall temperature effectively. The results provide reference to optimization design.

Optimal design of a high homogeneous and small-size shim coil for atomic spin gyroscope based on 0-1 linear programming

2020 ◽  
Vol 64 (1-4) ◽  
pp. 165-172
Author(s):  
Dongge Deng ◽  
Mingzhi Zhu ◽  
Qiang Shu ◽  
Baoxu Wang ◽  
Fei Yang
Keyword(s):  
Linear Programming ◽  
Power Consumption ◽  
Low Power ◽  
Optimization Design ◽  
Structural Parameters ◽  
Axial Position ◽  
Low Power Consumption ◽  
Optimal Method ◽  
Atomic Spin ◽  
Shim Coil

It is necessary to develop a high homogeneous, low power consumption, high frequency and small-size shim coil for high precision and low-cost atomic spin gyroscope (ASG). To provide the shim coil, a multi-objective optimization design method is proposed. All structural parameters including the wire diameter are optimized. In addition to the homogeneity, the size of optimized coil, especially the axial position and winding number, is restricted to develop the small-size shim coil with low power consumption. The 0-1 linear programming is adopted in the optimal model to conveniently describe winding distributions. The branch and bound algorithm is used to solve this model. Theoretical optimization results show that the homogeneity of the optimized shim coil is several orders of magnitudes better than the same-size solenoid. A simulation experiment is also conducted. Experimental results show that optimization results are verified, and power consumption of the optimized coil is about half of the solenoid when providing the same uniform magnetic field. This indicates that the proposed optimal method is feasible to develop shim coil for ASG.

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