Papers by Author: Xu Liang Xie

Abstract: ECE R29 regulation has legally claimed that the survival space must be guaranteed for the safety for driver and front seat passenger in event of crash during design of truck cabin. In this paper, a finite element model of a high-top cabin of a heavy truck with a manikin on the driver seat was built with commercial code Hypermesh, The explicit finite element program Ls-Dyna was used to simulate the frontal pendulum impact on the high-top cab in the light of ECE R29 regulation. Deformation of the truck cabin and the survival space of the dummy were analyzed and discussed. Also, some suggestions were given to solve the contact possibility between steering column and the knees of manikin.

Abstract: For design of truck cabin, the survival space must be guaranteed for the safety for driver and front seat passenger in event of crash, which is the legal requirement described in ECE-R29 regulation. In this paper, a finite element model of a high-top cabin for heavy truck was built with commercial code Hypermesh, and a manikin according to ECE-R29 was added to the driver seat. The explicit finite element program Ls-Dyna was used to verify the roof strength and rear wall strength. Analysis and discussion on the deformation of the truck cabin and the survival space of the dummy were presented. The survival space of the cab was proved to be sufficient for the safety of the driver.

Abstract: A new idea, using chirplet as the staff to define fractal dimension, is proposed in this paper, based on self- similitude of knowing essence of things from collectivity to part, from macroscopy to microcosm, in fractal theory and chirplet transformation. Chirplet fractal dimension is defined as the sum of high-frequency values of decomposed signals. The edge of infrared image is detected through chirplet fractal dimension, experimental results show that this new algorithm is simple and effective to detect whole contour and detail information, and is better than other traditional operators.

Abstract: In order to keep the temperature of Light emitting diode (LED) lamp below some limitation, a finned plain-plate heat-pipe was presented and numerically investigated to predict heat transfer performance under natural convection. Two kinds of fin configurations were studied. It is found that 30° is the worst orientation for the fin configuration with the tops of every other two channels covered, while the worst orientation is around 60° for the fin configuration with channel tops opened. The thermal conductivity of fin material only has mild effect on the cooling capacity with 7 % difference when its thermal conductivity varies from 50 to 200 W/(m·k). The latter configuration has better thermal performance than the former at the same orientation, especially at relatively low inclined angle.

Abstract: In order to verify thermal comfort of a 12-meter-long highway sleeper coach equipped with a four-ducted air-conditioning system, the thermal environment inside the passenger compartment was numerical investigated with RNG k-ε turbulence model. Also, discrete ordinates radiation model was applied to consider the effect of solar irradiation. The characteristic distribution of the airflow organization and temperature field were obtained and compared with experiment results. Results show that the air flow and temperature distribution inside the passenger compartment are not uniform and greatly influenced by solar radiation and air inlet parameters.

Abstract: In order to improve the rollover crashworthiness of coach, three roof beam structures commonly used in coach were established with finite element models for the rollover simulation, then the energy absorption, acceleration and body pillar deformation were analyzed. The simulation results show that circle-curved transition and non-curved transition on the roof have better collision performance. Especially, the latter not only reduces the acceleration peak value, but also transfers more collision energy to the offside lateral. The whole coach body will be involved in deformation, thus, the intrusion of survival space would be reduced. Finally, the complete vehicle skeleton finite element model of a 6127-type high-bed coach was built, and the influences of circle-curved transition and non-curved transition on the roof in rollover test were analyzed.

Abstract: In order to verify whether a new kind heat pipe heat sink can meet the requirement of high energy chip cooling or not, an experiment was conducted under heating and cooling process with a constant airflow rate. The transient heat exchange rate and transient temperature response of four thermocouples mounted on the upwind surface of the heat sink condenser were obtained. Results show that heat resistance decreases with increase in heat transfer rate under heating process, and the heat resistance is about 0.22K/W with the airflow rate 40m³/h. The transient temperature response is also analyzed with theory.