Simulation Analysis of Metro Station Construction Fire Based on FDS

2012 ◽  
Vol 446-449 ◽  
pp. 2093-2096 ◽  
Author(s):  
Hong De Wang ◽  
Tie Jun Cui

Taking the Hongqi west road station construction of Dalian metro line 2 as an example, the regularities of the temperature and the smoke concentration distribution are analyzed. Basing on FDS, the simulation model of the metro station fire is set up. Assume six fire points in the station to simulate the smoke diffusion velocity and the personnel evacuation time in fire. Results show that the chimney effect is obvious at the back of the station. The highest temperature of every export is 180°C and the lowest temperature is 40°C during the effective duration. The time duration can meet the needs of the personnel evacuation from the fire metro station. Basing on the analysis of variation of the smoke flows and the temperature, the metro station project is reasonable.

2014 ◽  
Vol 633-634 ◽  
pp. 1303-1310
Author(s):  
Jing Ke Du ◽  
Shu Han Wang ◽  
Ting Bin Song ◽  
Teng Teng Kang

The bearing lubrication system flow distribution design of the transmission was realized with a new system modeling method, targeted at the problem of a certain type of transmission’s bearings’ sintering. The heat-generated model and the flow-required model of the bearings and the gears were set up, and the required lubrication flow was obtained. The simulation model of the system flow distribution was established, the simulation analysis toward the dynamic characteristic of the transmission’s lubrication flow’s distribution was performed, and the results of the simulation analysis and the test were analyzed comparatively. The result showed that the simulation model matched the test result well, proving the effectiveness and correctness of the model of the transmission’s flow distribution.


2014 ◽  
Vol 945-949 ◽  
pp. 2568-2572
Author(s):  
Si Yuan Wang ◽  
Guang Sheng Ren ◽  
Pan Nie

The test rig for hydro-pneumatic converter used in straddle type monorail vehicles was researched, and its electro-pneumatic proportional control system was set up and simulated based on AMESim/Simulink. Compared fuzzy-PID (Proportion Integral Derivative) controller with PID controller through fuzzy logic tool box in Simulink, the results indicate that, this electro-pneumatic proportional control system can meet design requirements better, and fuzzy-PID controller has higher accuracy and stability than PID controller.


Author(s):  
Mahyar Asadi ◽  
Ghazi Alsoruji

Weld sequence optimization, which is determining the best (and worst) welding sequence for welding work pieces, is a very common problem in welding design. The solution for such a combinatorial problem is limited by available resources. Although there are fast simulation models that support sequencing design, still it takes long because of many possible combinations, e.g. millions in a welded structure involving 10 passes. It is not feasible to choose the optimal sequence by evaluating all possible combinations, therefore this paper employs surrogate modeling that partially explores the design space and constructs an approximation model from some combinations of solutions of the expensive simulation model to mimic the behavior of the simulation model as closely as possible but at a much lower computational time and cost. This surrogate model, then, could be used to approximate the behavior of the other combinations and to find the best (and worst) sequence in terms of distortion. The technique is developed and tested on a simple panel structure with 4 weld passes, but essentially can be generalized to many weld passes. A comparison between the results of the surrogate model and the full transient FEM analysis all possible combinations shows the accuracy of the algorithm/model.


2021 ◽  
Author(s):  
Qiongxiao Wu ◽  
Jianjun Wang ◽  
Jingming Chen ◽  
Pengzheng Li

Abstract Based on the one-dimensional simulation model of lubricating oil system is established and analyzed by using FLOWMASTER software, this paper proposes a new method of optimizing lubricating oil system by PID technology. Ensure that the configuration requirements and control strategies of the relevant accessories of the simulation model are satisfied with the design requirements. Firstly, by simulating lubricating oil pressure fluctuation and lubricating oil flow distribution under Open/Close Valve in different opening and closing time, the optimal opening/closing time of Open/Close Valve is determined to be 0.2 s and 0.5 s respectively. Secondly, by writing the controller script file combined with a controller to realize automatic unloading relief valve simulation, determine the relief valve pressure regulating range of 0∼0.38 MPa, For precision of constant pressure valve of oil spill, the simulation results show that the average 10 m3/h flow caused by pressure changes of about 0.06 MPa. Under the flow sudden change signal of about 40 m3/h, the maximum pressure change is less than 0.1 MPa. Through the simulation results, it is found that most of the lubrication parts in the original design have the phenomenon of flow redundancy, which causes unnecessary pump power loss. The system is optimized by PID technology. By comparing the simulation results before and after optimization, it is found that the speed of constant displacement pump could be changed in time by PID controller, and the flow redundancy could be improved significantly, so the lubricating oil system could be lower consumption and achieve the purpose of optimization.


Author(s):  
Longjia Chu ◽  
Baihe Zhu ◽  
T. F. Fwa

Overnight repairs and resurfacing of runway or taxiway pavements are common in busy airports. The time window available for such repair and resurfacing works is often limited. A common problem encountered is to ensure that the newly compacted asphalt mixture has cooled down sufficiently before receiving aircraft loadings, so as to avoid premature deformation and failure of the asphalt mixture. In this regard, a simulation model that provides a prediction of the temperature–time variation trend of each compacted pavement lift in a multi-lift asphalt course laying would be a valuable planning tool for temperature control. Information on the temperature cooling trend of an asphalt layer helps to estimate the time duration available for effective compaction during laying, as well as the time lapse needed before the pavement is sufficiently stable to receive traffic. A finite element simulation model is presented in this study to predict the temperature–time variation trends of successive asphalt lifts in a multi-lift asphalt mixture laying operation. The numerical model was developed based on the theory of thermodynamics taking into account the heat transfer effects of solar radiation, convection, and conduction. The model was calibrated and validated using data from a field trial involving a two-lift and a three-lift laying of asphalt mixtures. Illustrative examples are presented to demonstrate the applications of the simulation model as a temperature control planning tool for repair and resurfacing operations of airport pavements.


2013 ◽  
Vol 433-435 ◽  
pp. 63-66
Author(s):  
Jiang Yong

In this paper, out-moving jaw crusher machine is regarded as the research object and we established the simulation model of virtual prototype based on Nastran. Through the simulation analysis of the movement process, trajectories of moving jaw side plate and a movable jaw toggle plate and related parameters were obtained and compared and verify the simulation model and theory model. The results show that: the simulation model reflects the motion characteristics of the theoretical model well. So it provides theoretical reference for improvement of dynamic performance analysis and structure design of jaw crusher and has important application value in engineering.


2013 ◽  
Vol 864-867 ◽  
pp. 2418-2421
Author(s):  
Li Yang ◽  
Jian Lin Li ◽  
Shi Wei Luo

The tectonic stress field plays an important role in the research of crustal stability, fault activity and the geological disaster effect. On the basis of related geological data, ANSYS and FLAC3D are applied in this paper to set up a reasonable geological structure model and boundary conditions, aiming at making a numerical simulation analysis of tectonic stress field in the southeast of the Qinghai-Tibet plateau. The result and the measured data fit better, which provides a reference for the further study of the project.


Author(s):  
Alaa Hasan ◽  
Tarek ElGammal ◽  
Ryoichi S. Amano ◽  
Essam E. Khalil

Accurate control of thermal conditions in large space buildings like an underground metro station is a significant issue because passengers’ thermal comfort must be maintained at a satisfactory level. The large eddy simulation (LES) model was adopted while using the computational fluid dynamics (CFD) software “STAR CCM+” to set up a CFD station model to predict static air temperature, velocity, relative humidity and predicted mean vote (PMV), which indicates the passengers’ thermal comfort. The increase in the number of passengers using the model station is taken into consideration. The studied cases covered all the possible modes of the station box, these modes are (1) the station box is empty of trains, (2) the presence of one train inside the station box, (3) the presence of two trains inside the station box. The objective is to bring the passengers’ thermal comfort in all modes to the acceptable level. The operation of under platform exhaust (UPE) system is considered in case of train presence inside the station box. The use of UPE is more energy efficient than depending entirely on the air conditioning system to maintain the thermal conditions comfortable.


1994 ◽  
Vol 42 (4) ◽  
pp. 467 ◽  
Author(s):  
OJ Reichman ◽  
E Roberts

A number of hypotheses have been proposed to explain the mechanisms that promote coexistence among sympatric rodents in North American deserts. In an effort to determine how the distribution of seeds influences foraging patterns and coexistence in a three-species community of heteromyid rodents, we developed a computer simulation model that determines the efficiency of foraging for animals of different sizes. Specifically, the simulation determines how long it would take a forager to gather sufficient energy for 24 h if the animal stopped at seed patches of certain densities. The analyses were conducted for naturally occurring seed distributions and densities, for simulated normal and uniform distributions at natural densities, and for natural distributions at seed densities one-third those known to occur naturally. The results indicate that, under natural distributions and densities, each of the three species possessed unique optima for utilising seed patches of different density. However, when either the seed distribution or density differed from actual values, all three species had identical optima. The implications of these results for promoting coexistence are discussed.


Author(s):  
V. C. S. Ferreira ◽  
C. S. S. M. Cordeiro ◽  
J. W. Kaehler

Pulverized coal with low average heating, producing ashes with high percentage of silica, is fired inside the furnaces of a Thermal Power Plant (TPP) of Candiota, State of Rio Grande do Sul, Brazil. The produced hot flue gas heats the water of the ECONOMIZER 01 (ECO 01) placed inside the exhausted duct. Distorted velocity profile at inlet of ECO 01 and high concentration of abrasive particles of flue gas cause drastic erosion. So intensive has been the abrasive action that some well-identified tubes end up collapsing. The unpredictable fail has caused many non-scheduled stops of the TPP. A study focused on the reduction this effect, was set up years ago. The paper shows part of this study end present results, obtained from the numerical simulation analysis of the flue gas flow. Some technical solutions are suggested to reduce the erosion of tubes providing that avoiding it showed be impossible.


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