scholarly journals Initial study of an alternative technology aimed at measuring and controlling the flow rate in air conditioning ducts

2021 ◽  
Vol 13 (8) ◽  
pp. 168781402110346
Author(s):  
Andrei Testi ◽  
Marcio Abud Marcelino ◽  
Francisco Antonio Lotufo ◽  
Teófilo Miguel de Souza
Keyword(s):  
Fluid Dynamics ◽  
Flow Control ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Air Conditioning ◽  
Hot Wire ◽  
Numeric Simulation ◽  
Ansys Cfx ◽  
Certification Requirement

This paper states that there might have around 1000 small size business jets (until nine occupants) flying across the world equipped with flow control and regulating shut-off valves that uses hot wire anemometer devices to regulate massflow rate from the bleed airflow to supply the air-conditioning and pressurization systems. However, these valves present low reliability in the field. The purpose of this paper is to evaluate the implications of a flow control and regulating shut-off valve with a non-intrusive airflow measurer device under the perspective of fluid mechanics. The Venturi technology that is commonly used technology, given its construction simplicity, precision, and broad use in the industry, is selected to substitute the flow control and regulating shut-off valves with hot wire anemometer of the mentioned small size business jets applications. This paper has adopted a numeric simulation approach utilizing the ANSYS-CFX computational fluid dynamics software to verify both the differential pressure at the Venturi device and its correspondent mass flow rate to supply the air conditioning systems of some small size business jets, considering the mass-flow rate as requested by the FAA certification requirement (0.55 lb/min per occupant). This paper shows that a mass-flow rate control and regulating shut-off valve with a Venturi device, of 1 inch and β of 0.67, is compliant with the minimum fresh air flow requested by the FAA certification requirement to operate in some small size business jets. Besides that, the software ANSYS-CFX is also effective to support the engineering analysis of flow field characteristics inherent to the applications of internal compressible flow. The numeric simulation utilizing the ANSYS-CFX computational fluid dynamics software outlined herein can lay the basis for further research related to the design of a flow control and regulating shut-off valves with a Venturi device.

Computational Fluid Dynamics Performance Estimation of Turbo Booster Vacuum Pump

2003 ◽  
Vol 125 (3) ◽  
pp. 586-589 ◽  
Author(s):  
H.-P. Cheng ◽  
C.-J. Chen , ◽  
P.-W. Cheng ,
Keyword(s):  
Fluid Dynamics ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Vacuum Pump ◽  
Performance Estimation ◽  
High Mass ◽  
Rotor Speed ◽  
Low Mass ◽  
Pump Inlet

The CFD performance estimation of turbo booster vacuum pump shows the axial vortex and back flow is evident when the mass flow rate is increased. The pressure is increased from the pump inlet to the outlet for the low mass flow rate cases. But for high mass flow rate cases, the pressure is increased until the region near the end of the rotor then decreased. The calculated inlet pressure, compression ratio, and pumping speed is increased, decreased, and decreased, respectively, when the mass flow rate is increased. The pumping speed is increased when the rotor speed is increased.

Design and Optimization of the Restrictor of a Race Car

2015 ◽  
Author(s):  
Prithvi Raj Kokkula ◽  
Shashank Bhojappa ◽  
Selin Arslan ◽  
Badih A. Jawad
Keyword(s):  
Fluid Dynamics ◽  
Pressure Drop ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Air Flow ◽  
Intake Manifold ◽  
Maximum Pressure ◽  
Cross Sectional ◽  
Formula Sae

Formula SAE is a student competition organized by SAE International. The team of students design, manufacture and race a car. Restrictions are imposed by the Formula SAE rules committee to restrict the air flow into the intake manifold by putting a single restrictor of 20 mm. This rule limits the maximum engine power by reducing the mass flow rate flowing to the engine. The pull is greater at higher rpms and the pressure created inside the cylinder is low. As the diameter of the flow path is reduced, the cross sectional area for flow reduces. For cars running at low rpm when the engine requires less air, the reduction in area is compensated by accelerated flow of air through the restrictor. Since this is for racing purpose cars here are designed to run at very high rpms where the flow at the throat section reach sonic velocities. Due to these restrictions the teams are challenged to come up with improved restrictor designs that allow maximum pressure drop across the restrictor’s inlet and outlet. The design considered for optimizing a flow restrictor is a venturi type having 20 mm restriction between the inlet and the outlet complying with the rules set by Formula SAE committee. The primary objective of this work is to optimize the flow restriction device that achieves maximum mass flow and minimum pull from the engine. This implies the pressure difference created due to the cylinder pressure and the atmospheric pressure at the inlet should be minimum. An optimum flow restrictor is designed by conducting analysis on various converging and diverging angles and coming up with an optimum value. Venturi type is a tubular pipe with varying diameter along its length, through which the fluid flows. Law of governing fluid dynamics states that the “Velocity of the fluid increases as it passes through the constriction to satisfy the principle of continuity”. An equation can be derived from the combination of Bernoulli’s equation and Continuity equation for the pressure drop due to venturi effect. [1]. A Computational Fluid Dynamics (CFD) tool is used to calculate the minimum pressure drop across the restrictor by running a series of analysis on various converging and diverging angles and calculating the pressure drop. As a result, an optimum air flow restrictor is achieved that maximizes the mass flow rate and minimizes the engine pull.

Analysis and Optimization of Steam Duct for Improving Performance of Steam Cleaner

2012 ◽  
Vol 195-196 ◽  
pp. 52-55
Author(s):  
Jian Hua Wang ◽  
Yun De Shen ◽  
Dong Ji Xuan ◽  
Tai Hong Cheng ◽  
Zhen Zhe Li
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Quadratic Programming ◽  
Numerical Method ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Optimization Algorithm ◽  
Sequential Quadratic Programming ◽  
High Performance

Not only the price of a steam cleaner but also the performance of it should be considered to improve the competitive power of the products. In this study, a steam duct was optimized by changing the length of guide line for compensating the drawback of the unbalanced mass flow rate of steam from each outlet. For evaluating the mass flow rate of each outlet, a commercial CFD(computational fluid dynamics) code was used. In the process of the optimization, SQP(sequential quadratic programming) optimization algorithm was applied. The numerical method in this study can be widely used to develop a high performance domestic steam cleaner.

Effect of Condenser Temperature and Speed on one A/C System

2011 ◽  
Vol 314-316 ◽  
pp. 686-690
Author(s):  
Cheng Jun Pan ◽  
Yi Da Tang
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Air Conditioning ◽  
Systems Design ◽  
Test System ◽  
Coefficient Of Performance ◽  
Two Phase ◽  
Flow Measurements ◽  
Air Conditioning System

This study describes the results on the performance of one vehicle air conditioning system. The coefficient of performance, evaporator cooling capacity, compressor power consumption, total mass flow rate, vapor mass flow rate, liquid mass flow rate and oil in circulation, pressures and temperatures of refrigerant at every component (inlets and outlets) are measured and analyzed with the variation of the outside temperatures at the evaporator and condenser, the speed of the compressor, refrigerant charge and oil charge. The systematical experimental results obtained from this real-size test system depict the relations between the above parameters in a vehicle air conditioning system, which constitute a useful source for vehicle air conditioning systems design and analysis. The vapor quality (two-phase flow) measurements realized in this work provide an extremely important tool for diagnosing the system performances.

Mass flow-rate control unit to calibrate hot-wire sensors

2007 ◽  
Vol 44 (2) ◽  
pp. 189-197 ◽  
Author(s):  
F. Durst ◽  
K. Haddad ◽  
A. Al-Salaymeh ◽  
Shadi Eid ◽  
B. Ünsal
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Rate Control ◽  
Control Unit ◽  
Hot Wire ◽  
Flow Rate Control

Factors of Influence on the Leakage of Brush Seals

2020 ◽  
Author(s):  
Alexander Fuchs ◽  
Johann Göttler ◽  
Oskar J. Haidn
Keyword(s):  
Fluid Dynamics ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Interaction Model ◽  
Structure Interaction ◽  
Preliminary Results ◽  
Mechanics Model ◽  
Factors Of Influence ◽  
Brush Seals

Abstract Based on previous research from the authors a modeling approach for brush seals is developed further. Each individual bristle is reproduced in both the fluid dynamics and the structural mechanics model. An investigation regarding the influence of the free bristle height and the sealing gap on the leakage mass flow rate is carried out. Results are compared to experimental and literature data. Furthermore, preliminary results of the segregated fluid-structure interaction model are presented briefly, and matched to literature data.

scholarly journals CONDENSOR DESIGN ANALYSIS WITH KAYS AND LONDON SURFACE DIMENSIONS

SINERGI ◽  
2020 ◽  
Vol 24 (2) ◽  
pp. 81
Author(s):  
Dedik Romahadi ◽  
Nanang Ruhyat ◽  
L. B. Desti Dorion
Keyword(s):  
Pressure Drop ◽  
Mass Flow Rate ◽  
Air Temperature ◽  
Mass Flow ◽  
Flow Rate ◽  
Air Conditioning ◽  
Tube Length ◽  
Air Conditioner ◽  
Heat Transfer Area ◽  
Existing Data

The use of condensers in air conditioning units is more common in large-capacity units than in ones with a smaller capacity. Air conditioning provides comfort and freshness to an air-conditioned room. It should be noted that each room has a different heat load, which affects the specifications of the condenser used. The accuracy with which appropriate condenser specifications are determined affects the performance of the air conditioner. Thus, considering how important condenser needs are, it is necessary to design condensers with optimal performance, which adhere to proven standards. To achieve this, the design of a condenser should be based on the results of the smallest condenser dimensions of three types of surfaces, as they are intended for a limited place. This condenser design uses the standard dimensions of the Kays and London charts. Data is collected by measuring the results of temperature and enthalpy of a refrigerant at desuperheating and condensation, inlet air temperature, outlet air temperature, refrigerant mass flow rate, and air mass flow rate. The results of the compact condenser design are based on existing data, which is obtained from the smallest design results. The result uses the type of Surface CF-8.72(c) with a heat transfer area of 0.259 m2, a total tube length of 9.5 m, crossing tube length 0.594 m and a pressure drop of 3778 Pascal (Pa) on the side of a tube. This design fulfills the stipulated requirements, as the pressure drop is less than the specified maximum limit in most units.

scholarly journals EXPERIMENTAL AND NUMERICAL INVESTIGATION OF METASTABLE FLOW OF REFRIGERANT R-22 THROUGH CAPILLARY TUBE

2018 ◽  
Vol 18 (1) ◽  
pp. 41-62
Author(s):  
Esam M Abed ◽  
Ammar A K Fathi
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Capillary Tube ◽  
Numerical Data ◽  
Design And Optimization ◽  
Metastable Region ◽  
Ansys Cfx ◽  
Commercial Code ◽  
Suction Line

This study presents an experimental investigation of metastable region take place forrefrigerant flow through adiabatic and non-adiabatic capillary tube of window type airconditioner. Large numbers of experiments are carried out to explain the effect of length ofstraight and helical capillary tube on metastable region under adiabatic and non-adiabaticconditions. for the case of adiabatic capillary tube, three different length are selected(70,100 and 150) cm and two helical capillary tube, the length of each tube is 100 cm withtwo coil diameters (2 and 6) cm. For the non-adiabatic capillary tube, the straight capillarytube suction line is 150 cm while the length of non-adiabatic helical capillary tube is 200 cmwith 8 cm coil diameter. The results show that the length is the most influence parameterson beginning of metastable region. In addition the helical coil tube effect on the beginningof metastable region. As well as for the adiabatic and non-adiabatic capillary tube it isconcluded that mass flow rate is the main parameters on beginning of metastable region.Also effect of length and coiling on both pressure drop and mass flow rate are discussed.The CFD commercial code, ANSYS CFX 16.1 based on finite volume method using Kturbulencemodel considering the homogeneous flow between phases applied to straightcapillary tube. The present numerical data has been validated with the present workexperimental data and with other researchers. A good agreement is obtained which can belead to use ANSYS CFX 16.1 in the design and optimization of capillary tube in airconditioner.

scholarly journals Modeling Validation and Control Analysis for Controlled Temperature and Humidity of Air Conditioning System

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Jing-Nang Lee ◽  
Tsung-Min Lin ◽  
Chien-Chih Chen
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Air Conditioning ◽  
Thermal System ◽  
Control Analysis ◽  
Air Conditioning System ◽  
Temperature And Humidity ◽  
Control Criteria ◽  
And Control

This study constructs an energy based model of thermal system for controlled temperature and humidity air conditioning system, and introduces the influence of the mass flow rate, heater and humidifier for proposed control criteria to achieve the controlled temperature and humidity of air conditioning system. Then, the reliability of proposed thermal system model is established by both MATLAB dynamic simulation and the literature validation. Finally, the PID control strategy is applied for controlling the air mass flow rate, humidifying capacity, and heating, capacity. The simulation results show that the temperature and humidity are stable at 541 sec, the disturbance of temperature is only 0.14°C, 0006 kgw/kgdain steady-state error of humidity ratio, and the error rate is only 7.5%. The results prove that the proposed system is an effective controlled temperature and humidity of an air conditioning system.

Sign in / Sign up

Export Citation Format

Share Document