Experimental investigation on transverse ceiling flame length and temperature distribution of sidewall confined tunnel fire

Tunnel fire is a part of applied thermal problems. With increase of transient temperature of the tunnel fire on the structure surface (i.e. tunnel lining), the heat transfer from the surface is possibly varying transient temperature distribution within the structure. The transient temperature distribution is also possibly damaging the composition of structure (micro-crack) because of critical damage temperature. Therefore, the transient temperature distribution has a significantly important role on defining mechanical and physical properties of structure and determining thermal-induced damaged region. The damage at pre-period stage of tunnel fire is perhaps more significant than that at the other period stages because of thermal gradient. Consequently, a theoretical model was developed for simplifying complicated thermal engineering during pre-period stage of tunnel fire. A hollow solid model (HSM) in a combination of dimensional analysis and heat transfer theory with Bessel?s Function and Duhamel?s Theorem were employed to verify a theoretical equation for dimensionless transient temperature distribution (DTTD) under linear transient thermal loading (LTTL). Experimental and numerical methods were also adopted to approve the results from this theoretical equation. The heating rate (M) is a primary variable for discussing DTTD on three means. The heating rate of 10.191, 10 and 240?C/min were applied to experimental and numerical studies. The experimental and numerical results are consistent with the theoretical solution, successfully verifying that the theoretical solution can predict the DTTD well in field. This equation can be used for thermal/tunnel engineers to evaluate the damaged region and to obtain the parameters related to DTTD.

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Peak Temperature Correlation and Temperature Distribution during Joining of AZ80A Mg Alloy by FSW – A Numerical and Experimental Investigation

Strojniški vestnik – Journal of Mechanical Engineering ◽

10.5545/sv-jme.2020.6566 ◽

2020 ◽

Vol 66 (6) ◽

pp. 395-407 ◽

Cited By ~ 1

Author(s):

p Sevvel ◽

S.D. Dhanesh Babu ◽

R. Senthil Kumar

Keyword(s):

Experimental Investigation ◽

Temperature Distribution ◽

Quadratic Equation ◽

Peak Temperature ◽

Mg Alloy ◽

Element Analysis ◽

Temperature Correlation ◽

Friction Stir ◽

Az80a Mg Alloy ◽

Experimental Values

A quadratic equation has been developed based on experimental measurements to estimate the peak temperature in the friction stir welding (FSW) process during the joining of AZ80A Mg alloys. The numerical simulation of the FSW process was performed by employing COMSOL software to predict and calculate the distribution of temperature on the various regions of the parent metal and the welded joints. The predicted and finite element analysis (FEA) simulating the results of the distribution of peak temperatures were found to be consistent with the experimental values. In addition to this, a parametric experimental investigation was conducted to identify the most influential process parameter that plays a significant role in the peak temperature distribution during FSW of AZ80A Mg alloy. Linear contributions by the input process parameters of FSW, namely, traversing speed, rotating tool speed and axial force on the peak temperature were observed to be 32.82 %, 41.65 % and 21.76 %, respectively.

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An Experimental Investigation of Burning Droplets of Emulsified Marine Fuel Oils with Water

Journal of Ship Research ◽

10.5957/jsr.1995.39.1.95 ◽

1995 ◽

Vol 39 (01) ◽

pp. 95-101

Author(s):

Cherng-Yuan Lin ◽

Chein-Ming Lin ◽

Che-Shiung Cheng

Keyword(s):

Experimental Investigation ◽

Flame Length ◽

Fuel Oil ◽

Burning Time ◽

Marine Fuel ◽

Oil Emulsion ◽

Fuel Oils ◽

Oil Emulsions ◽

O 15 ◽

Time Required

An experimental investigation is presented of the influences of emulsification of marine fuel oils A and C with water on the micro-explosion phenomenon and combustion characteristics of a burning droplet. The amount of surfactant and water-to-oil ratio by volume in the emulsion are varied to observe the variations of ignition delay, flame length, time required to attain the maximum flame length, duration as well as intensity of micro-explosion, flame appearance, and overall burning time. The measurements show that the emulsification effects on the combustion of marine fuel oils A and C are different. A droplet of C-oil emulsion is shown to be influenced by the addition of water and surfactant more significantly. The micro-explosion phenomena of droplets of A-and C-oil emulsions are seen to occur after and before their ignition, respectively. In addition, separate combinations of water and surfactant content exist for these fuel oils to achieve better emulsification effects on combustion. Droplets of emulsions with W/O = 15/85, E% = 2% for fuel oil A and W/O = 25/75, E% = 1% for fuel oil C are found to have the most violent droplet-disruption phenomenon and the longest flame length.

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