A method of analyzing the productive capacities of working pits on the basis of the ventilation factor

1973 ◽  
Vol 9 (6) ◽  
pp. 673-676
Author(s):  
V. N. Vylegzhanin ◽  
É. I. Vitkovskii ◽  
A. G. Krekov
Keyword(s):  
Ventilation Factor

Relation Between the Incidence of Ascites Syndrome and the Ventilation Factor in Broiler Chickens

2008 ◽  
Vol 3 (5) ◽  
pp. 334-336 ◽  
Author(s):  
M.H. Movassagh Ghazani ◽  
A.R. Karami ◽  
A.R. Ahmadzadeh ◽  
J. Dolgharish
Keyword(s):  
Broiler Chickens ◽  
Ventilation Factor ◽  
Ascites Syndrome

Biomass solid fuel and acute respiratory infections: The ventilation factor

2006 ◽  
Vol 209 (5) ◽  
pp. 445-450 ◽  
Author(s):  
Anayo Fidelis Akunne ◽  
Valérie R. Louis ◽  
Mamadou Sanon ◽  
Rainer Sauerborn
Keyword(s):  
Solid Fuel ◽  
Respiratory Infections ◽  
Acute Respiratory Infections ◽  
Ventilation Factor

Evolution of pool fire plume characteristics during the depressurization process of an aircraft cargo compartment

2018 ◽  
Vol 36 (4) ◽  
pp. 362-375 ◽  
Author(s):  
Cong Li ◽  
Rui Yang ◽  
Yina Yao ◽  
Zhenxiang Tao ◽  
Hui Zhang
Keyword(s):  
Mass Loss ◽  
Loss Rate ◽  
Mass Loss Rate ◽  
Ambient Air ◽  
Pool Fire ◽  
Flame Height ◽  
Fire Plume ◽  
Activation Effect ◽  
Centerline Temperature ◽  
Ventilation Factor

This article presents an experimental investigation on the pool fire plume characteristics in a full-scale depressurized aircraft cargo compartment. The effects of decreasing pressure and vent flow rate on the fire characteristics such as flame shape, flame puffing, flame height, and centerline temperature were analyzed. The results show that during the depressurization process, the ventilation had an activation effect on the mass loss rate, and its increment had a linear relationship with the dimensionless ventilation factor. In addition, the larger depressurized rate caused the larger dimensionless ventilation factor and further resulted in the larger increment of mass loss rate. The flame puffing frequency was determined by the ratio of the gas density in the flame area of that in the ambient air, which increased with the drop of pressure. For flame centerline temperature, there was a counteraction area in the flame intermittent region, where the centerline temperature had almost no difference before and after the depressurization. The conclusions could provide the theoretical base and reference materials for the fire disaster in the cargo compartment of real aircrafts.

Determination of the Combined Ventilation Factor and Capacitance for Ice Crystal Aggregates from Airborne Observations in a Tropical Anvil Cloud

2008 ◽  
Vol 65 (2) ◽  
pp. 376-391 ◽  
Author(s):  
Paul R. Field ◽  
J. Heymsfield ◽  
Aaron Bansemer ◽  
Cynthia H. Twohy
Keyword(s):  
Particle Size ◽  
Water Vapor ◽  
Water Content ◽  
Numerical Models ◽  
Mean Value ◽  
Ice Crystal ◽  
Ice Water Content ◽  
Water Vapor Mixing Ratio ◽  
Ice Water ◽  
Ventilation Factor

Abstract The ventilation factor and capacitance used in numerical models to represent ice crystal aggregates directly affects the growth rate of the ice crystal aggregates, and consequently the sink of atmospheric water vapor. Currently, numerical models that prognose ice water content (IWC) and water vapor mixing ratio represent the capacitance and ventilation factor of precipitation-sized particles with simplified geometries, such as hexagonal plates. The geometries of actual precipitation-sized particles are often more complex, and a test of the values being employed is needed. Aircraft observations obtained during a Lagrangian spiral descent through the sublimation zone of a tropical anvil cloud have been used to determine an estimate of combined dimensionless capacitance and ventilation factor for the nonpristine geometries exhibited by ice crystal aggregates. By combining measurements of bulk ice water content, the particle size distribution, and environmental subsaturation, the change in ice water content was modeled throughout the spiral descent and compared with observations of the change in ice water content. Uncertainties resulting from potential systematic biases in the measurements and parameterizations used in the analysis were investigated with sensitivity tests. Most of the uncertainty was related to an assumed maximum potential bias in the measurement of IWC of ±45%. The resulting combined ventilation factor and dimensionless capacitance value was 1.3 (with a range of 0.6–1.9, defined by 68% of sensitivity test trials) for a particle size–weighted mean value of (Sc)1/3(Re)1/2 = 14.9 ± 1.7, where Sc is the Schmidt number and Re is the Reynolds number. Results from commonly adopted combinations of ventilation factor relations and capacitances are compared with the observations presented here, and, finally, surrogate dimensionless capacitances are suggested that when combined with commonly used ventilation factor relations are consistent with the results presented herein.

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