Aerodynamic Sounds Generated by Circular Wires Set up in a Horizontal Plane in a Uniform Air Flow

2000 ◽  
Vol 2000 (0) ◽  
pp. 238
Author(s):  
Hiroki MATSUMOTO ◽  
Kohshi NISHIDA ◽  
Kenichi SAITOH
Keyword(s):  
Horizontal Plane ◽  
Air Flow ◽  
Set Up

Temperature Distribution of Hot Air Flow in Heating Zone for Drying Application

2014 ◽  
Vol 627 ◽  
pp. 153-157
Author(s):  
Nawadee Srisiriwat ◽  
Chananchai Wutthithanyawat
Keyword(s):  
Temperature Distribution ◽  
Air Temperature ◽  
Power Supply ◽  
Air Flow ◽  
Heating Zone ◽  
Velocity Control ◽  
Rectangular Duct ◽  
Air Velocity ◽  
Hot Air ◽  
Set Up

The temperature distribution of hot air flow in heating zone of a rectangular duct has been investigated for drying application. The experimental set-up consists of a heater and a fan to generate the hot air flow in the range of temperature from 40 to 100°C and the range of air velocity between 1.20 and 1.57 m/s. An increase of the heater power supply increases the hot air temperature in the heating zone while an increase of air velocity forced by fan decreases the initial temperature at the same power supply provided to generate the hot air flow. The temperature distribution shows that the hot air temperature after transferring through air duct decreases with an increase of the length of the rectangular duct. These results are very important for the air flow temperature and velocity control strategy to apply for heating zone design in the drying process.

Performance Analysis of Eductor Used for Main Control Room Ventilating in Nuclear Power Plant

2017 ◽  
Author(s):  
Xin Yu ◽  
Yuqing Lin ◽  
Yan Zhang
Keyword(s):  
Flow Rate ◽  
Nuclear Power ◽  
Air Flow ◽  
Test System ◽  
Air Pressure ◽  
Air Flow Rate ◽  
Control Room ◽  
Entrainment Ratio ◽  
Pressurized Water ◽  
Set Up

This paper proposes the experimental research for the performance of the air eductor used in main control room (MCR). The air eductor is used for emergency ventilating in advanced passive pressurized water reactor in accident. The compress air is supplied to the eductor as a power source and the indoor air is suctioned to the eductor. The performance of the eductor is related to the habitability of MCR. The entrainment ratio and the air pressure of discharge side are the main concerned performance. The entrainment ratio is a value that resulted from the compress air flow rate divided by the suction air flow rate. A test system was set up to test the performance of eductor. The experimental results show that the entrainment ratio of rectangle nozzle with compress air pressure 0.76MPa, 0.80MPa and 0.83MPa were 15.02, 15.04 and 15.06, respectively.

Testing and Validation of Long Trains Under High Flow and Gradient Conditions

2012 ◽  
Author(s):  
Abe Aronian ◽  
Kim Wachs ◽  
Michelle Jamieson ◽  
Karen Carriere ◽  
Edward W. Gaughan
Keyword(s):  
Air Flow ◽  
Field Testing ◽  
Signal Propagation ◽  
Operating Conditions ◽  
Distributed Power ◽  
Extensive Field ◽  
Train Length ◽  
Set Up ◽  
Operating Instructions ◽  
Work Done

The need to extend train lengths has been a primary business target of the railway industry, due to its obvious benefits. However, winter train operating conditions, excessive in-train slack action, deterioration of air brake signal propagation and the added stress on infrastructure and equipment has naturally kept the average train lengths at bay. The introduction of advanced equipment, new concepts and strategies have now enabled Canadian Pacific to change this mindset. Long Train make up is now very possible, taking into account the Distributed Power configuration. Making a very long train resemble a series of short trains coupled together, each with its own locomotives, synchronously connected to the Lead unit’s commands, makes such trains very safe and efficient. Extensive Field Testing and Train Simulation work done over the last two years at CP has shown that with the use of Multiple Remote Locomotive set-up, it is in fact very possible to safely contemplate extending the limits of today’s maximum allowed 60 CFM of total train air flow, into uncharted territory, possibly approaching a total of 90 CFM. CP has pursued to implement on a permanent basis, operating instructions that would permit Multiple Distributed Power trains to depart from a train brake test location with combined air flow of up to 90 CFM, provided the flow at each DP locomotive consist is not greater than 60 CFM and train length sections between locomotives are not exceeded. This paper investigates the operation of Distributed Power trains at higher levels of air flow and, through detail field testing and evaluation techniques, substantiates the validity of extending the safety limits of train leakage and gradient for such trains.

scholarly journals Experimental Investigation of the Air Exchange Effectiveness of Push-Pull Ventilation Devices

Energies ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 5817
Author(s):  
Sven Auerswald ◽  
Carina Hörberg ◽  
Thibault Pflug ◽  
Jens Pfafferott ◽  
Constanze Bongs ◽  
...  
Keyword(s):  
Heat Dissipation ◽  
Residential Buildings ◽  
Air Flow ◽  
Operation Mode ◽  
Ventilation System ◽  
Field Measurements ◽  
Gas Analysis ◽  
Decentralised Systems ◽  
Set Up ◽  
Air Exchange

The increasing installation numbers of ventilation units in residential buildings are driven by legal objectives to improve their energy efficiency. The dimensioning of a ventilation system for nearly zero energy buildings is usually based on the air flow rate desired by the clients or requested by technical regulations. However, this does not necessarily lead to a system actually able to renew the air volume of the living space effectively. In recent years decentralised systems with an alternating operation mode and fairly good energy efficiencies entered the market and following question was raised: “Does this operation mode allow an efficient air renewal?” This question can be answered experimentally by performing a tracer gas analysis. In the presented study, a total of 15 preliminary tests are carried out in a climatic chamber representing a single room equipped with two push-pull devices. The tests include summer, winter and isothermal supply air conditions since this parameter variation is missing till now for push-pull devices. Further investigations are dedicated to the effect of thermal convection due to human heat dissipation on the room air flow. In dependence on these boundary conditions, the determined air exchange efficiency varies, lagging behind the expected range 0.5 < εa < 1 in almost all cases, indicating insufficient air exchange including short-circuiting. Local air exchange values suggest inhomogeneous air renewal depending on the distance to the indoor apertures as well as the temperature gradients between in- and outdoor. The tested measurement set-up is applicable for field measurements.

The Thurston Rotor Cowl for Air-Cooled Engines

1935 ◽  
Vol 39 (293) ◽  
pp. 445-447
Author(s):  
A. P. Thurston
Keyword(s):  
Boundary Layer ◽  
Radial Flow ◽  
Air Flow ◽  
Cooling Effect ◽  
Pressure Gradients ◽  
Aircraft Engines ◽  
Undesirable Effect ◽  
Forward Flow ◽  
Set Up ◽  
Horse Power

One of the main problems in connection with the development of air-cooled engines appears to consist in securing adequate cooling without increasing the head resistance above that of corresponding water-cooled engines.This problem particularly applies to large air-cooled engines which are limited in size by cooling difficulties. Air-cooled engines for windmill planes and helicopters for alternate slow and fast flying present a further problem, because such aircraft engines will be required to develop maximum horse-power when the speed of translation is lowest.The airflow over the nose of a bulky body, such as that of an aeroplane, diverges radially in every direction from its axis. Such radial flow tends to overshoot laterally, at its core, the periphery of the engine or other obstruction and so depart from the contour thereof, with the result that a considerable turbulence is set up. Such turbulence has also the undesirable effect of causing a reversal of the pressure gradients, and a corresponding reversed or forward flow of air, in the boundary layer behind the engine, thereby creating a ” dead “ area or areas and so considerably reducing the cooling effect of the general air flow and increasing the turbulence.

Experimental Study of Heat Storage Unit Made of PCM-gypsum Composite Integrated with the Ventilation System of the Building

2017 ◽  
Author(s):  
Maciej Jaworski ◽  
Hanna Jędrzejuk ◽  
Rafał Laskowski
Keyword(s):  
Heat Storage ◽  
Air Flow ◽  
Ventilation System ◽  
Ambient Air ◽  
Heat Transfer Process ◽  
Night Time ◽  
Storage Unit ◽  
Regenerative Heat ◽  
Air Temperatures ◽  
Set Up

In the paper a special heat storage unit for building applications is presented. It has a form of a ceiling panel that is made of PCM-gypsum mortar composite and it contains internal channels for air flow, since it is designed as a part of ventilation system of the building. The panel works as a regenerative heat exchanger with phase change material (PCM) as a prevailing heat storage medium. When a melting point of PCM is properly chosen it is possible that air temperature flowing into the building reach a level corresponding to thermal comfort conditions, regardless the temperature at the intake. Warm air (during a day) releases heat basically to PCM causing its melting. During night time cool ambient air is heated up while it takes back heat accumulated in PCM. An experimental set-up based on the above concept was developed. A series of tests in different conditions (for variable inlet air temperatures, air flow rates) were performed. Information on thermal performance of the ceiling panel as well as detailed data on heat transfer process were obtained and discussed in the paper.

Three-dimensional simulation and experimental investigation of three-dimensional printed guiding devices on lattice-apron compact spinning

2020 ◽  
pp. 004051752098258
Author(s):  
Malik YH Saty ◽  
Nicholus Tayari Akankwasa ◽  
Jun Wang
Keyword(s):  
Experimental Investigation ◽  
Air Flow ◽  
Flow Analysis ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Yarn Properties ◽  
3D Printed ◽  
Dimensional Simulation ◽  
Compact Spinning ◽  
Set Up

The compact spinning system with a lattice apron utilizes air-flow dynamics to condense fibers in a bunch and enhance the yarn properties. One of the main challenges with this method is the lack of a comprehensive understanding of the air-flow field's effect in the condensing zone. This work presents a numerical and experimental investigation of the effects of three-dimensional (3D) printed guiding devices on the air-flow characteristics and yarn properties. Firstly, the 3D numerical model of the compact spinning system was set up based on the compact spinning machine geometrical dimensions. Secondly, different 3D prototypes were developed, simulated, and analyzed using computational fluid dynamics based on ANSYS software. The prototypes (A-type, B-type, and C-type), selected according to the simulation results, were then 3D printed to enable further experimental investigation. Air-flow analysis results in the air-suction flume area exhibiting a very high negative pressure, and the centerline zone was characterized by high velocity. Experimental results revealed that the three yarns spun with guiding devices had better strength, hairiness, and evenness than those spun without a guiding device. The model developed can be further improved and utilized for commercial purposes and is anticipated to improve compact spun yarn properties significantly.

scholarly journals Investigation of the motion processes of wastewater in sewerage of high-rise buildings

2018 ◽  
Vol 33 ◽  
pp. 02013
Author(s):  
Valentina Pomogaeva ◽  
Lyudmila Metechko ◽  
Dmitry Prokofiev ◽  
Tamara Narezhnaya
Keyword(s):  
Cross Section ◽  
Air Flow ◽  
Gravity Drainage ◽  
High Rise ◽  
Flow Pressure ◽  
Waste Flow ◽  
Set Up ◽  
Water Outflow ◽  
Sewage Waste

When designing, constructing and operating sewage pipelines in high-rise buildings, issues of failure-free operation of a network arise. Investigation of the processes of wastewater moving allows identifying problem areas during operation, assessing the possibility of obstructions and breakdowns of plumbing traps on the gravity drainage sections of the pipeline. The article performs the schemes of the water outflow from the floor sewer into the riser, including the places where the riser is bent, of air delivery to the working riser under the change of the direction of drain movement with the dropout line set-up, with the installation of an automatic anti-vacuum valve, with the installation of the ventilation pipeline. Investigations of the process of sewage waste flow in a sewage riser were carried out, in order to select the appropriate structure. The authors consider structure features of some sections of sewerage in high-rise buildings. The exhaustion value in the riser is determined from the rarefactions that occur below the compressed cross-section of the riser and the loss of the air flow pressure coming from the atmosphere into the riser during the deflooding of the liquid. Preventing the formation of obstructions and breakdowns of plumbing traps is an integral part of sewage networks.

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