Yan D.-J.,Harbin Institute of Technology |
Liu X.-S.,Harbin Institute of Technology |
Li J.,Harbin Institute of Technology |
Li J.,Zhejiang Yinlun Machinery Co. |
And 2 more authors.
Journal of Central South University of Technology (English Edition) | Year: 2010
The effect of strain hardening and strain softening behavior of flow stress changing with temperature on welding residual stress, plastic strain and welding distortion of A7N01-T4 aluminum alloy was studied by finite simulation method. The simulation results show that the weld seam undergoes strain hardening in the temperature range of 180-250 °C, however, it exhibits strain softening at temperature above 250 °C during welding heating and cooling process. As a result, the strain hardening and strain softening effects counteract each other, introducing slightly influence on the welding residual stress, residual plastic strain and distortion. The welding longitudinal residual stress was determined by ultrasonic stress measurement method for the flat plates of A7N01-T4 aluminum alloy. The simulation results are well accordant with test ones. © 2010 Central South University Press and Springer-Verlag Berlin Heidelberg.
Qi Y.L.,Caterpillar Inc. |
Dong L.C.,Chongqing University |
Liu H.,Zhejiang Yinlun Machinery Co. |
Puzinauskas P.V.,University of Alabama |
Midkiff K.C.,University of Alabama
International Journal of Automotive Technology | Year: 2012
It is well known that in-cylinder flow is very important factor for the performance of SI engine. An appropriate in-cylinder flow pattern can enhance the turbulence intensity at spark time, therefore increasing the stability of combustion, reducing emission and improving fuel economy. In this paper, the effect of intake port design on in-cylinder flow is studied. It is found a vortex existed at the upper side of intake port of a production SI engine used in the study, during the intake stroke, which will reduce both tumble ratio and volumetric efficiency. A minor modification on intake port is made to eliminate the vortex and increase tumble ratio while keeping volumetric efficiency at the same level. It is demonstrated that the increase in tumble in the new design results in a 20 per cent increase in the fuel vaporization. In this study, both KIVA and STAR-CD are used to simulate the engine cold flow, as well as ICEM CFD and es-ice used as pre-processor respectively due to the complexity of engine geometry. Simulation results from KIVA and STAR-CD are compared and analyzed. © 2012 The Korean Society of Automotive Engineers and Springer-Verlag Berlin Heidelberg.
Huang Y.,Zhejiang University |
Liu Z.,Zhejiang University |
Lu G.,Zhejiang Yinlun Machinery Co. |
Yu X.,Zhejiang University
International Communications in Heat and Mass Transfer | Year: 2014
CFD/CHT simulations have been widely used in simulating cross flow compact heat exchangers, but the calculating accuracy is commonly limited. The multi-scale thermal analysis approach was adopted to study an intercooler, one of the representative examples of cross flow heat exchangers in automotive cooling systems. With the application of mesh refinement and datum interpolation technique, the inside flow and heat transfer mechanism were analyzed, the pressure and temperature data were also calculated. The model was validated with experimental data based on wind tunnel tests, and the results show that the multi-scale coupled calculation is in good agreement with experimental values, especially in the heat transfer simulations. The research of the inside flow and heat transfer mechanism is capable of providing a basis for optimization of compact heat exchangers. © 2014 Elsevier Ltd.
Zhejiang Yinlun Machinery Co. | Date: 2012-09-11
The present invention discloses an exhaust gas inlet structure of an exhaust gas recirculation (EGR) Cooler which includes a water shell, a gas inlet pipe, a bellow, an insulated pipe, an inlet chamber, a pre-cooling water chamber and a main board. The water shell is equipped with a water inlet pipe. Its main feature is the insulated pipe is placed within the bellow and connected with the gas inlet pipe at one end while the other end is suspended. The large-bore end of the inlet chamber is connected with the main board to form a gas inlet cavity while leaving a space to form a coolant channel between the joining part and the water shell. An external surface of a middle pipe body connects to the bellow to form a pre-cooling cavity connected to the coolant channel. The advantages of the present invention are as follow: newly-added pre-cooling water chamber reduces the wall temperature of the main board and the inlet chamber; newly-added supporting in the middle part of the insulated pipe improves the vibration-proof function of the insulated pipe; the special structure of the inlet chamber increases the ability of the axial displacement compensation. The above-mentioned improvement of the present invention significantly improves the reliability of the EGR cooler.
Xiao B.-L.,Zhejiang University |
Yu X.-L.,Zhejiang University |
Han S.,Zhejiang University |
Lu G.-D.,Zhejiang Yinlun Machinery Co. |
Xia L.-F.,Zhejiang Yinlun Machinery Co.
Zhejiang Daxue Xuebao (Gongxue Ban)/Journal of Zhejiang University (Engineering Science) | Year: 2010
Numerical simulation method was adopted to investigate the effects of the fin structures and parameters on the thermal hydraulic performance in a charged air cooler (CAC). Three dimension k-ε turbulence model, block-structured grid and fluid-solid coupling method combined with shell conduction model were adopted and DOE (Orthogonal experimental design) method was used to simulate the fluid flow and heat transfer performances of 18 virtual geometry units. The range and variance analyses were carried out, and wind tunnel tests were used to validate the effectiveness of the method. The investigation indicates the effects of fin structure and pitch on heat transfer performance are most notable, and those of the fin height and fin wavy amplitude follows, as for fluid flow resistance, the effect of fin height is most obvious, and those of the wavy amplitude and pitch are second to it. The effect of wavy length on performance can be ignored. The simulation findings validated by wind tunnel tests are consistent with engineering experiences.