AIR FLOW SENSOR

2021 ◽  
Author(s):  
Андрей Евгеньевич Скугаров ◽  
Светлана Анатольевна Микаева
Keyword(s):  
Flow Rate ◽  
Air Flow ◽  
Air Pressure ◽  
Flow Sensor ◽  
Pitot Tube ◽  
Sensor Design ◽  
Air Flow Rate ◽  
Fixed Plate

В статье описаны датчики массового расхода воздуха. Авторы приводят типы различных конструкций, принцип действия и способы определения расхода воздуха. В основе конструкции датчика лежит трубка Пито и закреплённая пластина, которая деформируется под давлением воздуха. The article describes the sensors of mass air flow.The authors give the types of various structures, the principle of operation and methods for determining the air flow rate. The sensor design is based on a Pitot tube and a fixed plate that deforms under air pressure.

Parametric study on pressure-based packed bed adsorption system for air dehumidification

2021 ◽  
pp. 095440892110073
Author(s):  
V Sureshkannan ◽  
TV Arjunan ◽  
D Seenivasan ◽  
SP Anbuudayasankar ◽  
M Arulraj
Keyword(s):  
Genetic Algorithm ◽  
Taguchi Method ◽  
Flow Rate ◽  
Uptake Rate ◽  
Air Flow ◽  
Packed Bed ◽  
Air Pressure ◽  
Dew Point ◽  
Adsorption System ◽  
Air Flow Rate

Compressed air free from traces of water vapour is vital in many applications in an industrial sector. This study focuses on parametric optimization of a pressure-based packed bed adsorption system for air dehumidification through the Taguchi method and Genetic Algorithm. The effect of operational parameters, namely absolute feed air pressure, feed air linear velocity, and purge air flow rate percent on adsorption uptake rate of molecular sieve 13X-water pair, are studied based on L25 orthogonal array. From the analysis of variance, it has been found that absolute feed air pressure and purge air flow rate percent were the parameters making significant improvement in the adsorption uptake rate. A correlation representing the process was developed using regression analysis. The optimum adsorption conditions were obtained through the Taguchi method and genetic algorithm and verified through the confirmation experiments. This system can be recommended for the industrial and domestic applications that require product air with the dew point temperature below 0°C.

Oral Air Pressure and Nasal Air Flow Rate on Levator Veli Palatini Muscle Activity in Patients Wearing a Speech Appliance

1995 ◽  
Vol 32 (5) ◽  
pp. 382-389 ◽  
Author(s):  
Takashi Tachimura ◽  
Hisanaga Hara ◽  
Takeshi Wada
Keyword(s):  
Flow Rate ◽  
Muscle Activity ◽  
Neural Control ◽  
Air Flow ◽  
Air Pressure ◽  
Electromyographic Activity ◽  
Air Flow Rate ◽  
Circular Area ◽  
Pharyngeal Bulb ◽  
Levator Veli Palatini

This study was designed to determine if levator veli palatini muscle activity can be elicited by simultaneous changes in oral air pressure and nasal air flow when a speech appliance is in place. The speech appliances routinely worn by 15 subjects were each modified experimentally by drilling a hole in the vertical center of the pharyngeal bulb. The air flow rate into the nasal cavity through the opening in the bulb was altered by changing the circular area of the opening in the bulb from the occluded condition (Condition I), to circular area of 12.6 mm2 (4 mm in diameter; Condition II), and then to 38.5 mm2 (7 mm in diameter; Condition III). Electromyographic activity was measured from the levator veli palatini muscle with changes in nasal air flow rate and oral air pressure. Levator veli palatini muscle activity was correlated with changes in nasal air flow and oral air pressure. Increases in levator veli palatini muscle activity were associated with increases in nasal air flow rate compared to oral air pressure changes. The results indicated that aerodynamic variables of nasal air flow and oral air pressure might be involved in the neural control of speech production in individuals wearing a speech appliance, even if the subjects exhibit velopharyngeal incompetence without using a speech appliance. Also, the stimulating effect of bulb reduction therapy on velopharyngeal function might be achieved through the change in aerodynamic variables in association with the bulb reduction.

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.

scholarly journals Development of Virtual Air Flow Sensor Using In-Situ Damper Performance Curve in VAV Terminal Unit

Energies ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 4307 ◽  
Author(s):  
Hyo-Jun Kim ◽  
Jae-Hun Jo ◽  
Young-Hum Cho
Keyword(s):  
Relative Error ◽  
Flow Rate ◽  
Air Flow ◽  
Measurement Procedure ◽  
Flow Sensor ◽  
Performance Curve ◽  
Air Flow Rate ◽  
Terminal Unit ◽  
Input Variables

In this study, we developed a virtual air flow sensor using an in-situ damper performance curve to secure the stability of control of the variable air volume (VAV) terminal unit, and also established the in-situ measurement procedure. The minimum air flow rate of the VAV terminal unit was related to the energy consumption, it was important to determine the minimum air flow rate suitable for the situation of each room in terms of energy saving. However, it was difficult to set the minimum air flow rate low setpoint due to the low accuracy of the air flow sensor of the VAV terminal unit. This paper suggested a virtual air flow sensing method using an in-situ damper performance curve in the VAV terminal unit. The input factors of the virtual sensor were developed on the basis of the supply fan speed and damper opening ratio, which could be easily obtained from the existing control system. In addition, the in-situ measurement procedure of the virtual air flow sensor was developed by dividing the procedure into five steps. Finally, reliability of the virtual air flow sensor was evaluated through uncertainty analysis of input variables and relative error analysis, in comparison with the conventional air flow rate measurement method. The developed virtual air flow sensor was found to have an uncertainty of up to 8.8%, and it was also found that the closer to the maximum the values of the input variables, the lower the uncertainty. In addition, verification of relative error with respect to the measured values by the hot-wire anemometer was conducted by varying operation conditions to a total of 12 cases, and as a result, relative error was found to be up to 5.6%. In addition, the results of long-term experiment showed that relative error was within about 9.5%, and thus, the feasibility for field application and control was confirmed.

scholarly journals Performance Investigation of MQL Parameters Using Nano Cutting Fluids in Hard Milling

Fluids ◽  
2021 ◽  
Vol 6 (7) ◽  
pp. 248
Author(s):  
Tran Minh Duc ◽  
Tran The Long ◽  
Ngo Minh Tuan
Keyword(s):  
Flow Rate ◽  
Cutting Forces ◽  
Air Flow ◽  
Cutting Temperature ◽  
Air Pressure ◽  
Cutting Fluid ◽  
Al2o3 Nanoparticles ◽  
Air Flow Rate ◽  
Hard Milling ◽  
Lubrication Performance

Machining difficult-to-cut materials is one of the increasingly concerned issues in the metalworking industry. Low machinability and high cutting temperature generated from the contact zone are the main obstacles that need to be solved in order to improve economic and technical efficiency but still have to ensure environmental friendliness. The application of MQL method using nano cutting fluid is one of the suggested solutions to improve the cooling and lubricating performance of pure-MQL for machining difficult-to-cut materials. The main objective of this paper is to investigate the effects of nanofluid MQL (NFMQL) parameters including the fluid type, type of nanoparticles, air pressure and air flow rate on cutting forces and surface roughness in hard milling of 60Si2Mn hardened steel (50–52 HRC). Analysis of variance (ANOVA) was implemented to study the effects of investigated variables on hard machining performance. The most outstanding finding is that the main effects of the input variables and their interaction are deeply investigated to prove the better machinability and the superior cooling lubrication performance when machining under NFMQL condition. The experimental results indicate that the uses of smaller air pressure and higher air flow rate decrease the cutting forces and improve the surface quality. Al2O3 nanoparticles show the better results than MoS2 nanosheets. The applicability of soybean oil, a type of vegetable oil, is proven to be enlarged in hard milling by suspending nanoparticles, suitable for further studies in the field of sustainable manufacturing.

scholarly journals Model of thermal buoyancy in cavity-ventilated roof constructions

2021 ◽  
pp. 174425912098418
Author(s):  
Toivo Säwén ◽  
Martina Stockhaus ◽  
Carl-Eric Hagentoft ◽  
Nora Schjøth Bunkholt ◽  
Paula Wahlgren
Keyword(s):  
Analytical Model ◽  
Flow Rate ◽  
Numerical Study ◽  
Air Flow ◽  
Wind Pressure ◽  
Air Flow Rate ◽  
Test Set ◽  
Air Cavity ◽  
Thermal Buoyancy ◽  
The Impact

Timber roof constructions are commonly ventilated through an air cavity beneath the roof sheathing in order to remove heat and moisture from the construction. The driving forces for this ventilation are wind pressure and thermal buoyancy. The wind driven ventilation has been studied extensively, while models for predicting buoyant flow are less developed. In the present study, a novel analytical model is presented to predict the air flow caused by thermal buoyancy in a ventilated roof construction. The model provides means to calculate the cavity Rayleigh number for the roof construction, which is then correlated with the air flow rate. The model predictions are compared to the results of an experimental and a numerical study examining the effect of different cavity designs and inclinations on the air flow rate in a ventilated roof subjected to varying heat loads. Over 80 different test set-ups, the analytical model was found to replicate both experimental and numerical results within an acceptable margin. The effect of an increased total roof height, air cavity height and solar heat load for a given construction is an increased air flow rate through the air cavity. On average, the analytical model predicts a 3% higher air flow rate than found in the numerical study, and a 20% lower air flow rate than found in the experimental study, for comparable test set-ups. The model provided can be used to predict the air flow rate in cavities of varying design, and to quantify the impact of suggested roof design changes. The result can be used as a basis for estimating the moisture safety of a roof construction.

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