Experimental Study of Fire Behavior in a Depressurized Aircraft Cargo Compartment

2017 ◽  
Author(s):  
Cong Li ◽  
Yina Yao ◽  
Zhenxiang Tao ◽  
Rui Yang
Keyword(s):  
Burning Rate ◽  
Oscillation Frequency ◽  
Dynamic Pressure ◽  
Flame Temperature ◽  
Fire Behavior ◽  
Federal Aviation Administration ◽  
Pressure Control ◽  
Rate Oscillation ◽  
Pressure Control System ◽  
Fire Experiments

To analyze the fire behavior in the dynamic pressure environment, a series of n-heptane pool fire experiments were conducted in an 8.11m × 4.16m × 1.67m simulated aircraft cargo compartment. The compartment is capable of mimicking flight environment from taking off to landing of the aircraft according to the standards of Federal Aviation Administration (FAA) by a pressure control system. Pool fires with 30cm diameter were tested under the dynamic pressure from 101kPa to 45kPa with various depressurization rates of 10kPa/min, 15kPa/min, 20kPa/min and 25kPa/min. Fire behavior such as burning rate, oscillation frequency and flame temperature were analyzed. The results revealed that the dynamic pressure influences the burning rate not only during the depressurization stage but also after depressurization. The oscillation frequency increases with the pressure decrease but has no relationship with depressurization rate. The flame temperature at different heights shows various tendencies with pressure.

Experiment Study of Cardboard Box Fire Behavior Under Dynamic Pressure in an Altitude Chamber

2015 ◽  
Author(s):  
Runhe Tian ◽  
Quanyi Liu ◽  
Rui Feng ◽  
Kewei Chen ◽  
Rui Yang ◽  
...  
Keyword(s):  
Radiative Heat ◽  
Dynamic Pressure ◽  
Ambient Pressure ◽  
Flame Temperature ◽  
Fire Behavior ◽  
Measurement Data ◽  
Safety Engineering ◽  
Mass Burning Rate ◽  
Experiment Study ◽  
Controlling System

Fires recently at low ambient pressure such as cruising airplane and high altitude airport have attracted great attention. Understanding fire behavior under low pressure is one of important fundamental problems for fire safety engineering design in forementioned environment. Observation of cardboard fires under dynamic pressure is of significant meaning to study continuous variation of fire behaviors of solid fuel during depressurization. An altitude chamber of 2×3×4.65 m3 with a powerful pressure controlling system was designed to observe fire behavior of cardboard fires under dynamic pressure. In the chamber, two configurations of cardboard boxes filled with shredded office paper were tested under dynamic pressures at descent rates: 5.46kPa/min, 10.92kPa/min, and 19.68kPa/min for both configurations. Measured parameters in this study include flame temperature, radiative heat flux, and mass burning rate. The measurement data were analyzed to reveal depressurization effect on fire behavior.

Experimental Study of Mass Burning Rate of Liquid Pool Fires Under Dynamic Pressure in an Altitude Chamber

2017 ◽  
Author(s):  
Zhenxiang Tao ◽  
Rui Yang ◽  
Cong Li ◽  
Yina Yao ◽  
Wei Wang
Keyword(s):  
Burning Rate ◽  
Dynamic Pressure ◽  
Ambient Pressure ◽  
Flame Temperature ◽  
Great Influence ◽  
Liquid Pool ◽  
Combustion Characteristics ◽  
Chamber Pressure ◽  
Pool Fires ◽  
Mass Burning Rate

To study the influence of dynamic pressure on the liquid combustion characteristics, two kind sizes of pool fires were studied under varied pressure rates, namely 100Pa/s, 200Pa/s, 300Pa/s from 90kPa to 38kPa in an altitude chamber which size is 2m*3m*4.65m. Combustion characteristics of n-heptane pool fires, such as mass burning rate, flame temperature, chamber pressure were measured in this research. Experiment results show that the mass burning rate of 20cm pool fires, decreases when the ambient pressure reduces, and the variation trend become more sharply when the dynamic pressure rate is increased, while 30cm pool fires at the beginning of the combustion stage almost remain constant, this is because fire heat feedback have a great influence on it. The results also show that compared to the radiation model, pressure model could be linear fitting better in a double logarithm coordinate, and oil pool fires under 300Pa/s of 20cm, 100Pa/s of 30cm the value of α obtained by the fitted curves were more closer to fixed pressure ones.

scholarly journals Designing Control System of Hypersonic Vehicle with Dynamic Pressure Constraints Considered

2019 ◽  
Vol 37 (1) ◽  
pp. 41-47
Author(s):  
Hongyang Xu ◽  
Yonghua Fan ◽  
Xi Tong ◽  
Jie Yan
Keyword(s):  
Control System ◽  
Optimal Control Theory ◽  
Dynamic Pressure ◽  
Pressure Control ◽  
Hypersonic Vehicle ◽  
State Equations ◽  
Integral Control ◽  
Pressure Control System ◽  
Scramjet Engine ◽  
Simulation Results

An airbreathing hypersonic vehicle(AHV) generally adopts a scramjet engine as its propulsion, which needs strict conditions of flight dynamic pressure. A new dynamic pressure control system is presented, in which the AHV autopilot directly uses dynamic pressure to track the dynamic pressure command. Firstly, the dynamic pressure model of the AHV is established and the state equations of dynamic pressure control are given. Then, the dynamic pressure control system is implemented using the LQR optimal control theory. The dynamic pressure error is augmented in order to add an integral control to track the dynamic pressure with zero steady error. The structure of the dynamic pressure control system is also obtained. The simulation results show that the dynamic pressure control system has a good performance for guaranteeing the dynamic pressure of the scramjet engine with the disturbance of drag and thrust considered.

PRESSURE CONTROL SYSTEM AT CEMENTATION OF WELLS

2017 ◽  
pp. 62-67
Author(s):  
V. G. Kuznetsov ◽  
O. A. Makarov
Keyword(s):  
Control System ◽  
Oil And Gas ◽  
Pressure Control ◽  
Poor Quality ◽  
Technical Solution ◽  
Cement Slurry ◽  
Automated Control ◽  
Injection Speed ◽  
Pressure Control System ◽  
Effective Life

At cementing of casing of oil and gas wells during the process of injecting of cement slurry in the casing column the slurry can move with a higher speed than it’s linear injection speed. A break of continuity of fluid flow occurs, what can lead to poor quality isolation of producing formations and shorten the effective life of the well. We need to find some technical solution to stabilize the linear velocity of the cement slurry in the column. This task can be resolved with an automated control system.

Development of a Pressure Control System for Brace Treatment of Scoliosis

2012 ◽  
Vol 20 (4) ◽  
pp. 557-563 ◽  
Author(s):  
Eric Chalmers ◽  
Edmond Lou ◽  
Doug Hill ◽  
Vicky H. Zhao ◽  
Man-Sang Wong
Keyword(s):  
Control System ◽  
Pressure Control ◽  
Brace Treatment ◽  
Pressure Control System

Real-Time Micro-Fluidic Chip Pressure Control System Base on the Optical Interference

2014 ◽  
Vol 494-495 ◽  
pp. 1274-1277
Author(s):  
Kan Liu ◽  
Hao You
Keyword(s):  
Control System ◽  
Real Time ◽  
Measurement System ◽  
Interference Fringe ◽  
Pressure Control ◽  
Measured Data ◽  
Optical Interference ◽  
Interference Fringes ◽  
Pressure Control System

This article introduces a measurement system based on LabVIEW used for optical interference fringe on micro-fluidic chips. This system mainly uses cameras to capture real-time images of wedge interference fringe on micro-fluidic chips, then the collected images will be binarized by LabVIEW. The processed images will be divided by zone , determine the flatness and gap thickness of the micro-fluidic chips by interference fringes with different directions of deflection and numbers. Finally, feedback from measured data will be used to adjust the flatness and gap thickness of micro-fluidic chips in order to meet the requirement of tests.

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