Transitions between the multiple steady states in a natural ventilation system with combined buoyancy and wind driven flows

2007 ◽  
Vol 42 (10) ◽  
pp. 3500-3516 ◽  
Author(s):  
Jinchao Yuan ◽  
Leon R. Glicksman
Keyword(s):  
Natural Ventilation ◽  
Ventilation System ◽  
Steady States ◽  
Multiple Steady States

POVERTY TRAPS AND INFERIOR GOODS IN A DYNAMIC HECKSCHER–OHLIN MODEL

2012 ◽  
Vol 17 (6) ◽  
pp. 1227-1251 ◽  
Author(s):  
Eric W. Bond ◽  
Kazumichi Iwasa ◽  
Kazuo Nishimura
Keyword(s):  
Economic Theory ◽  
Steady State ◽  
World Economy ◽  
Steady States ◽  
The Other ◽  
Poverty Traps ◽  
Poverty Trap ◽  
Multiple Steady States ◽  
The World ◽  
State Capital

We extend the dynamic Heckscher–Ohlin model in Bond et al. [Economic Theory(48, 171–204, 2011)] and show that if the labor-intensive good is inferior, then there may exist multiple steady states in autarky and poverty traps can arise. Poverty traps for the world economy, in the form of Pareto-dominated steady states, are also shown to exist. We show that the opening of trade can have the effect of pulling the initially poorer country out of a poverty trap, with both countries having steady state capital stocks exceeding the autarky level. However, trade can also pull an initially richer country into a poverty trap. These possibilities are a sharp contrast with dynamic Heckscher–Ohlin models with normality in consumption, where the country with the larger (smaller) capital stock than the other will reach a steady state where the level of welfare is higher (lower) than in the autarkic steady state.

50 Multiple steady states in electrochemical reactors

1980 ◽  
Vol 35 (1-2) ◽  
pp. 396-404 ◽  
Author(s):  
George P. Sakellaropoulos ◽  
Brian G. Volintine
Keyword(s):  
Steady States ◽  
Multiple Steady States ◽  
Electrochemical Reactors

scholarly journals Intensification of Reactive Distillation for TAME Synthesis Based on the Analysis of Multiple Steady-State Conditions

Processes ◽  
2018 ◽  
Vol 6 (12) ◽  
pp. 241 ◽  
Author(s):  
Takehiro Yamaki ◽  
Keigo Matsuda ◽  
Duangkamol Na-Ranong ◽  
Hideyuki Matsumoto
Keyword(s):  
Liquid Flow ◽  
Reactive Distillation ◽  
Steady States ◽  
Vapor Flow ◽  
Multiple Steady States ◽  
Reflux Ratio ◽  
Flow Rates ◽  
Reaction Conversion ◽  
Reaction Performance ◽  
Separation Performances

Our previous study reported that operation in multiple steady states contributes to an improvement in reaction conversion, making it possible to reduce the energy consumption of the reactive distillation process for tert-amyl methyl ether (TAME) synthesis. This study clarified the factors responsible for an improvement in the reaction conversion for operation in the multiple steady states of the reactive distillation column used in TAME synthesis. The column profiles for those conditions, in which multiple steady states existed and those in which they did not exist, were compared. The vapor and liquid flow rates with the multiple steady states were larger than those when the multiple steady states did not exist. The effect of the duty of the intermediate condenser, which was introduced at the top of the reactive section, on the liquid flow rate for a reflux ratio of 1 was examined. The amount of TAME production increased from 55.2 to 72.1 kmol/h when the intermediate condenser was operated at 0 to −5 MW. Furthermore, the effect of the intermediate reboiler duty on the reaction performance was evaluated. The results revealed that the liquid and vapor flow rates influenced the reaction and separation performances, respectively.

The NO + CO reaction on clean Pt(lOO): Multiple steady states and oscillations

1988 ◽  
Vol 206 (1-2) ◽  
pp. 169-186 ◽  
Author(s):  
S.B. Schwartz ◽  
L.D. Schmidt
Keyword(s):  
Steady States ◽  
Multiple Steady States

scholarly journals Three-Dimensional Simulation of Wind-Driven Ventilation Through a Windcatcher With Different Inlet Designs

2019 ◽  
Vol 12 (4) ◽  
Author(s):  
Peter Abdo ◽  
Rahil Taghipour ◽  
B. Phuoc Huynh
Keyword(s):  
Wind Speed ◽  
Average Velocity ◽  
Natural Ventilation ◽  
Ventilation System ◽  
Three Dimensional ◽  
Cfd Modeling ◽  
Ansys Fluent ◽  
Wind Velocities ◽  
Dimensional Simulation ◽  
Convergent Inlet

Abstract Windcatcher is an effective natural ventilation system, and its performance depends on several factors including wind speed and wind direction. It provides a comfortable and healthy indoor environment since the introduced fresh air decreases the moisture content and reduces the pollutant concentration. Since the wind speed and its direction are generally unpredictable, it is important to use special inlet forms and exits to increase the efficiency of a windcatcher. In this study, computational fluid dynamics (CFD) modeling is implemented using ansys fluent to investigate the airflow entering a three-dimensional room through a windcatcher with different inlet designs. Three designs are studied which are a uniform inlet, a divergent inlet, and a bulging-convergent inlet. The airflow pattern with all inlets provided adequate ventilation through the room. With all the applied wind velocities (1, 2, 3, and 6 m/s) at the domain's inlet, the divergent inlet shape has captured the highest airflow through the room and provided higher average velocity at 1.2 m high enhancing the thermal comfort where most of the human occupancy occurs. With 6 m/s wind velocity, the divergent inlet has captured 2.55% more flow rate compared to the uniform inlet and 4.70% compared to the bulging-convergent inlet, and it has also provided an average velocity at 1.2 m high in the room of 7.16% higher than the uniform inlet and 8.44% higher than the bulging-convergent inlet.

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