scholarly journals CALCULATION PROCEDURE OF AIR SUPPLY RATE IN PRESSURIZED SMOKE CONTROL BASED ON VENTILATION CALCULATION METHOD IN NORMAL TEMPERATURE AND EFFECT OF HEIGHT OF AIR RELEASE OPENING ON FIRE ROOM

2012 ◽  
Vol 77 (673) ◽  
pp. 115-120
Author(s):  
Masashi KISHIUE ◽  
Takayuki MATSUSHITA ◽  
Kouji FUJITA ◽  
Satoru TAKADA
Keyword(s):  
Calculation Method ◽  
Calculation Procedure ◽  
Smoke Control ◽  
Supply Rate ◽  
Air Supply

GENERAL METHOD FOR CALCULATING BUTT AND ANGLE WELDS FOR STRENGTH

2021 ◽  
pp. 28-33
Author(s):  
Yu. N. Vavilov ◽  
I. Yu. Skobeleva ◽  
I. A. Shirshova
Keyword(s):  
Calculation Method ◽  
Calculation Scheme ◽  
Calculation Procedure ◽  
Fillet Welds ◽  
Specific Design ◽  
Strength Of Materials ◽  
Butt Welds ◽  
Strength Based ◽  
Design Solutions ◽  
General Method

The existing methods for calculating butt and fillet welds are private, developed for specific design solutions that do not take into account the variety of weld shapes and the variety of combinations of forces and moments. The article provides a general method for calculating butt and fillet welds for strength, based on the calculation method for nominal stresses, adopted in the strength of materials. This technique was used without any changes for the calculation of butt welds, since the weld is an extension of the part. The calculation of fillet welds is based on two assumptions, on the basis of which a calculation scheme has been developed, which makes it possible to use the calculation method for rated stresses. The article proposes two design schemes, considers the calculation procedure and derives two generalized strength conditions for the verification calculation of butt and fillet welds.

On the instability of ventilated cavities

1966 ◽  
Vol 26 (3) ◽  
pp. 437-457 ◽  
Author(s):  
L. C. Woods
Keyword(s):  
Pressure Fluctuations ◽  
Unsteady Motion ◽  
Cavitation Number ◽  
The Body ◽  
Supply Rate ◽  
Velocity Fluctuations ◽  
Air Supply ◽  
Resonance Frequencies ◽  
Axis Of Symmetry ◽  
The Mathematical Model

It has been found that ventilated cavities extending behind hydrofoils, plates, and other two-dimensional bodies, oscillate when the air supply rate is sufficient to reduce the cavitation number to about one-fifth of its natural value. As the rate increases further, higher modes of oscillation occur in which the cavity–water interface supports several waves that are convected downstream towards the wake, which, owing to a pinching-off action replacing the usual entrainment sink, consists of a sequence of large bubbles drifting downstream. A theory of such flows that allows both for the convected velocity fluctuations in the cavity, and for the transport of bubble volume down the wake, is given in this paper. Coupled with a rather simple phenomenological relation between the pressure fluctuations within the cavity and the departure of the pinched-off rear portion of the cavity—explained in terms of the action of the re-entrant jet—this theory successfully predicts the resonance frequencies obtained in experiments by Silberman & Song.The theory also provides a solution of the more general problem of determining the fluctuations in the pressure distribution over the whole surface of the body, when it is in a prescribed unsteady motion along its axis of symmetry (the theory is confined to symmetrical bodies and flows). Thus the growth in drag due to a sudden increment in the upstream velocity can be predicted, and also the damping forces acting on the body when it is forced to oscillate at a given frequency. It is shown that in all cases the body is unstable.One important feature of the mathematical model chosen is that it completely avoids the presence of a time-dependent sink at infinity—with its associated infinite pressures—by conserving total volume of wake and cavity in just the same way as vorticity is conserved in unsteady aerofoil theory.

scholarly journals Proposal of Air Supply Smoke Control System about Stair-case Considering Stack Effect & Opening of the Outside Door

2020 ◽  
Vol 34 (5) ◽  
pp. 130-137
Author(s):  
Yongkwang Kim
Keyword(s):  
Performance Test ◽  
Control Method ◽  
Developed Countries ◽  
Smoke Control ◽  
Stack Effect ◽  
Proper Role ◽  
Air Supply ◽  
Safety Code ◽  
Entrance Door ◽  
Smoke Control System

Most of the special escape staircase smoke control systems for high-rise buildings in accordance with the national fire safety code NFSC 501A are constructed with smoke control only vestibule, making it difficult to expect a proper role in an emergency. This standard, which was created by introducing the concept of air supply pressurized smoke control 25 years ago, created Korea´s smoke control only vestibule, which was not found in developed countries, and has been mainly applied to it to fit into the poor architectural environment of the time. However, there is a fundamental flaw there, so the performance test for completion without occupants is passed, but in the presence of occupants, the performance does not come out properly and it is being blamed for being useless. In this regard, the author proposes a method of air supply pressurized smoke control for stair-case that avoid the smoke control method only vestibule, reduces the stack effect with good cost-effectiveness, and considers opening the outside entrance door of the stair-case.

scholarly journals A Comparative Study on Domestic and Foreign Standards for Air Supply for the Improvement of a Smoke Control System for High-Rise Buildings

2019 ◽  
Vol 33 (4) ◽  
pp. 105-111
Author(s):  
Hye-Won Kim ◽  
Byeong-Heun Lee ◽  
Seung-Hyeon Jin ◽  
Su-Gak Lee ◽  
Jung-Yup Kim ◽  
...  
Keyword(s):  
Control System ◽  
Comparative Study ◽  
Smoke Control ◽  
High Rise ◽  
Air Supply ◽  
Smoke Control System

Application of Computer Simulation Technique in Smoke Control System Design

2011 ◽  
Vol 255-260 ◽  
pp. 1848-1852
Author(s):  
Ying Chen ◽  
Si Cheng Li ◽  
Jie Ji
Keyword(s):  
Computer Simulation ◽  
Control System ◽  
System Design ◽  
Rapid Development ◽  
Design Parameters ◽  
Control System Design ◽  
Smoke Control ◽  
Air Supply ◽  
Supply Mode ◽  
Smoke Control System

The fire simulation technology is widely used with the rapid development of computer technology. Taking a 12-story building for calculation, numerical simulation method is used to analyze the wind speed distribution characteristics of opening stairwell door and lobby door under different air supply volume. Then the appropriate pressurized air supply mode and back pressure coefficient value under natural smoke venting have been recommended. The researches show that computer simulation can be used in smoke control system design to help determine pressurized air supply mode and design parameters, so as to solve difficult problems in engineering design.

Risk of Sick Leave Associated with Outdoor Air Supply Rate, Humidification, and Occupant Complaints

Indoor Air ◽  
2000 ◽  
Vol 10 (4) ◽  
pp. 212-221 ◽  
Author(s):  
DONALD K. MILTON ◽  
P. MARK GLENCROSS ◽  
MICHAEL D. WALTERS
Keyword(s):  
Sick Leave ◽  
Outdoor Air ◽  
Supply Rate ◽  
Air Supply
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