scholarly journals Investigation on Smoke Flow in Stairwells induced by an Adjacent Compartment Fire in High Rise Buildings

2019 ◽  
Vol 9 (7) ◽  
pp. 1431 ◽  
Author(s):  
Jun Zhang ◽  
Jingwen Weng ◽  
Tiannian Zhou ◽  
Dongxu Ouyang ◽  
Qinpei Chen ◽  
...  
Keyword(s):  
Temperature Distribution ◽  
Three Dimensional ◽  
Factor H ◽  
Maximum Temperature ◽  
Vertical Temperature ◽  
Location Factor ◽  
Index Model ◽  
Smoke Flow ◽  
Vertical Temperature Distribution ◽  
Fire Location

The aim of this study was to evaluate the transport phenomena of smoke flow and vertical temperature distribution in a 21-story stairwell with multiple fire locations and openings. A large eddy simulation (LES) method was used to model the smoke flow in a stairwell model with a set of simulation parameters, wherein the fire heat release rate (HRR) and fire location were varied. Based on the results, a wall attachment effect was found in three-dimensional figures. Moreover, with an increase in the fire HRR, the effects were more pronounced. The simulation results verified that the vertical temperature distribution is an index model with a natural logarithm, where the pre-finger factor and attenuation coefficient increase considerably in accordance with an increase in the fire HRR. Moreover, there was a decrease in the maximum temperature (Tm) with an increase in the fire location factor (h*) due to the upward thermal smoke. Moreover, heat mainly accumulates in the area above a fire source. However, h* has a slight influence on the time required to reach Tm within the range of 53–64 s. Furthermore, the direction of the airflow at each side opening in the stairwell varied in accordance with the variation in the fire location changes, and a regular calculation was carried out.

Electromagnetic performance and thermal analysis of a novel permanent magnet fluxed-switching coupler

2021 ◽  
pp. 1-18
Author(s):  
Lezhi Ye ◽  
Yulong Zhang ◽  
Mingguang Cao
Keyword(s):  
Temperature Distribution ◽  
Permanent Magnet ◽  
Permanent Magnets ◽  
Three Dimensional ◽  
Load Condition ◽  
Maximum Load ◽  
Maximum Temperature ◽  
The Novel ◽  
Transient Field ◽  
Three Dimensional Finite Element

To solve the problem of complex operating device and permanent magnets (PMs) demagnetization at high temperature, a new type of permanent magnet fluxed-switching coupler (PMC) with synchronous rotating adjuster is proposed. Its torque can be adjusted by rotating a switched flux angle between the adjuster and PMs along the circumferential direction. The structural feature and working principle of the PMC are introduced. The analytical model of the novel PMC was established. The torque curves are calculated in transient field by using the three-dimensional finite element method (3-D FEM). The temperature distribution of the novel PMC under rated condition is calculated by 3-D FEM, and the temperature distribution of the PM is compared with that of the conventional PMC. The simulation and test results show that the maximum temperature of copper disc and PM of the novel PMC are 100 °C and 48 °C respectively. The novel PMC can work stably for a long time under the maximum load condition.

An experimental and non-dimensional study on the vertical temperature distribution of a sealed ship engine room fire

2018 ◽  
Vol 165 ◽  
pp. 22-33 ◽  
Author(s):  
Jinhui Wang ◽  
Yu Jiao ◽  
Long Shi ◽  
Qimiao Xie ◽  
Guoqiang Li ◽  
...  
Keyword(s):  
Temperature Distribution ◽  
Vertical Temperature ◽  
Engine Room ◽  
Vertical Temperature Distribution

scholarly journals Numerical Simulation and Experimental Study on Temperature Distribution of Self-Lubricating Packing Rings in Reciprocating Compressors

2016 ◽  
Vol 2016 ◽  
pp. 1-14 ◽  
Author(s):  
Jia Xiaohan ◽  
Zhang Qingqing ◽  
Feng Jianmei ◽  
Peng Xueyuan
Keyword(s):  
Temperature Distribution ◽  
Pressure Ratio ◽  
Three Dimensional ◽  
Maximum Temperature ◽  
Transfer Model ◽  
Radial Temperature ◽  
Operational Conditions ◽  
External Cooling ◽  
Packing Rings ◽  
Compressor Reliability

The nonuniform abrasion failure and high-temperature thermal failure of packing rings have a significant influence on compressor reliability, particularly that of oil-free compressors. In this study, a test rig was constructed to measure the dynamic temperature of packing rings under different operational conditions in an oil-free reciprocating compressor. The dynamic axial and radial temperature distributions of the packing rings were obtained using an innovative internal temperature testing device that kept the thermocouples and packing box relatively static during compressor operation. A three-dimensional heat transfer model was also developed to analyze the temperature distribution of the packing boxes, piston rod, and cylinder during such operation. Good agreement was observed between the simulation results and experimental data, which showed an average relative error of less than 2.35%. The results indicate that the pressure ratio exerts a significant effect on the axial temperature distribution and determines which packing ring reaches the maximum temperature. They also show the average temperature to rise with an increase in the rotational speed and to fall with an improvement in the external cooling conditions. Finally, the material of the packing rings was found to affect the temperature gradient from their inner to outer surface.

scholarly journals VI. The vertical temperature distribution the atmosphere over England, and some remarks on the general and local circulation

1912 ◽  
Vol 211 (471-483) ◽  
pp. 253-278 ◽  
Keyword(s):  
Temperature Distribution ◽  
British Isles ◽  
Vertical Temperature ◽  
Local Circulation ◽  
The Past ◽  
Rubber Balloon ◽  
Vertical Temperature Distribution

During the past four years a considerable number of small free balloons carrying selfrecording instruments have been sent up in the British Isles, and sufficient observations have now accumulated to give some idea of the conditions which prevail over England, to a height of about 10 miles, in summer and winter, in cyclonic and anticyclonic weather. The method of obtaining observations is fully described in a publication of the Meteorological Office, M.O. 202. It will suffice here to state that a small selfrecording instrument, weighing 1 oz. (35 gr.), is attached by about 30 ft. (9 metres) of strong thread to a small rubber balloon. The balloon is 1 ft. diameter when unstretched. It is filled with hydrogen until it is expanded to about 1 m. diameter, securely tied up, and then let go. The balloons generally rise until they burst, and carry the instrument on the average to a height of 10 miles (16 km). A label offering a reward of 5 s . is attached to the instrument, and the reward is claimed and the instrument returned in two cases out of three.

Computational analysis of temperature distribution in microwave-heated potatoes

2020 ◽  
Vol 26 (6) ◽  
pp. 465-474
Author(s):  
Deepak Singh ◽  
Dhananjay Singh ◽  
Sattar Husain
Keyword(s):  
Mathematical Model ◽  
Temperature Distribution ◽  
Computational Analysis ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Maximum Temperature ◽  
Bacterial Inactivation ◽  
Food Material ◽  
Drying Time ◽  
Temperature Ranges

This research article reports the computational analysis of temperature distribution in microwave-heated convenience food such as potato. The detailed study of temperature (because temperature is a function of bacterial inactivation) and microwave powers along with drying time for the preservation of food material has been presented. Therefore, a mathematical model for potato sample is developed to predict the behavior of temperature distribution at each possible point and different shapes (slab, cylindrical, and spherical) of food material. The developed mathematical model is programmed by MATLAB software. Another parameter, microwave power is also a function of temperature. The ranging values of various microwave powers (125 W, 375 W, 625 W, 875 W, and 1250 W) along with different values of drying time (0 to 10 minutes) have been used for computation. The obtained results show the uniformity of temperature distribution throughout the whole product in the form of a three-dimensional structure. The model provides the minimum and maximum temperature ranges in specimens without performing an experiment which depicts the condition of bacterial inactivation.

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