Research on the Smoke Mass Flow Rate in One-Dimensional Spreading Stage in Tunnel with Multiple Fire Sources

The one-dimensional equations of surge in centrifugal compressors are solved graphically for the pressure head and mass flow rate as functions of time for a variety of situations, and the results are discussed in terms of the acoustical properties of the external piping. Two important parameters affecting the nature of the surge limit cycle are found to be simply related to the acoustic capacitance and acoustic inductance of the system.

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Modelling of a Single Passage Air PV/T Solar Collector: Experimental and Simulation Design

Processes ◽

10.3390/pr8070763 ◽

2020 ◽

Vol 8 (7) ◽

pp. 763

Author(s):

Noran Nur Wahida Khalili ◽

Mahmod Othman ◽

Mohd Nazari Abu Bakar ◽

Lazim Abdullah

Keyword(s):

Error Analysis ◽

Mass Flow Rate ◽

Mass Flow ◽

Flow Rate ◽

Solar Collector ◽

Total Efficiency ◽

Research Attention ◽

Air Mass ◽

One Dimensional ◽

Simulation Results

The hybrid photovoltaic/thermal solar collector has attracted research attention for more than five decades. Its capability to produce thermal energy simultaneously with electrical energy is considered attractive since it provides higher total efficiency than stand-alone photovoltaic or thermal systems separately. This paper describes theoretical and experimental studies of a finned single pass air-type photovoltaic/thermal (PV/T) solar collector. The performance of the system is calculated based on one dimensional (1D) steady-state analysis using one dimensional energy balance equations, where simulation was carried out using MATLAB. Experiments were carried out to observe the performance of the solar collector under changes in air mass flow rate. Experimental values on photovoltaic panel temperature and air temperature on both air inlet and outlet, together with the ambient temperature and solar radiation were measured. The simulation results were validated against the results obtained from experiments using the error analysis method, Root Mean Square Error. At a solar irradiance level of 800 to 900 W/m2, the thermal efficiency increases to 20.32% while the electrical efficiency increases to 12.01% when the air mass flow rate increases from 0.00015 kg/s to 0.01 kg/s. The error analysis shows that both experimental and simulation results are in good agreement.

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Calculations of the Flow of Natural Gas Through Critical Flow Nozzles

Journal of Basic Engineering ◽

10.1115/1.3425076 ◽

1970 ◽

Vol 92 (3) ◽

pp. 580-586 ◽

Cited By ~ 6

Author(s):

R. C. Johnson

Keyword(s):

Natural Gas ◽

Mass Flow Rate ◽

Mass Flow ◽

Flow Rate ◽

Pressure Range ◽

Gas Mixtures ◽

Empirical Method ◽

Critical Flow ◽

One Dimensional ◽

Rate Calculation

The mass flow rate of methane and 19 natural gas mixtures through critical flow nozzles has been calculated. The calculation assumes the flow to be one-dimensional and isentropic. The pressure range is 0 to 1000 psi and the temperature range is from 450 to 700 deg Rankine. From a study of the results, a simple empirical method for making this mass flow rate calculation is proposed. This method would apply to natural gas mixtures whose composition is known and whose components have no more than four carbon atoms.

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A One-Dimensional Analytical Method for Turbine Blade Preliminary Cooling Design

Volume 2C: Turbomachinery ◽

10.1115/gt2016-56783 ◽

2016 ◽

Author(s):

Chen Li ◽

Jian-jun Liu

Keyword(s):

Mass Flow Rate ◽

Turbine Blade ◽

Mass Flow ◽

Flow Rate ◽

Film Cooling ◽

Three Dimensional ◽

Cooling Effectiveness ◽

Film Cooling Effectiveness ◽

One Dimensional ◽

Cooling Design

The turbine blade cooling design is a complex procedure including one-dimensional preliminary cooling design, detailed two-dimensional design and fluid network analyses, and three-dimensional conjugate heat transfer and FEM predictions. Frequent alteration and modification of the cooling configurations make it unpractical to obtain all of three-dimensional design results quickly. Preliminary cooling design deals mainly with the coolant requirements and can be knitted into fluid network to look up the expected cooling structural style to promote three-dimensional geometry design. Previous methods to estimate the coolant requirements of the whole turbine blade in the preliminary cooling design were usually based on the semi-empirical air-cooled blade data. This paper combines turbine blade internal and external cooling, and presents a one-dimensional theoretical analytical method to investigate blade cooling performance, assuming that the coolant temperature increases along the blade span. Firstly, a function of non-dimensional cooling mass flow rate is derived to describe the new relationship between adiabatic film cooling effectiveness and overall cooling effectiveness. Secondly, a new variable related to film cooling is found to estimate the required adiabatic film cooling effectiveness without using the empirical correlations. Finally, a theoretical calculation about the relationship between non-dimensional cooling mass flow rate and overall cooling effectiveness well corresponds to semi-empirical air-cooled blade data within regular range of cooling efficiency. The currently proposed method is also a useful tool for the blade thermal analysis and the sensitivity analysis of coolant requirements to various design parameters. It not only can provide all the possible options at the given gas and coolant inlet temperatures to meet the design requirement, but also can give the third boundary conditions for calculating the blade temperature field. It’s convenient to use the heat transfer characteristic of internal cooling structures to estimate the coolant mass flow rate and the channel hydraulic diameter for both convection cooling and film cooling.

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Determination of critical operating and geometrical parameters in diesel injectors through one dimensional modelling, design of experiments and an analysis of variance

Proceedings of the Institution of Mechanical Engineers Part D Journal of Automobile Engineering ◽

10.1177/0954407017735262 ◽

2017 ◽

Vol 232 (13) ◽

pp. 1762-1781 ◽

Cited By ~ 5

Author(s):

Francisco J Salvador ◽

Marcos Carreres ◽

Marco Crialesi-Esposito ◽

Alejandro H Plazas

Keyword(s):

Design Of Experiments ◽

Mass Flow Rate ◽

Analysis Of Variance ◽

Mass Flow ◽

Flow Rate ◽

Control Volume ◽

Geometrical Parameters ◽

One Dimensional ◽

Injection Process ◽

Rate Profile

In this paper, a design of experiments and a statistical analysis of variance (ANOVA) are performed to determine the parameters that have more influence on the mass flow rate profile in diesel injectors. The study has been carried out using a one dimensional model previously implemented by the authors. The investigation is split into two different parts. First, the analysis is focused on functional parameters such as the injection and discharge pressures, the energizing time and the fuel temperature. In the second part, the influence of 37 geometrical parameters, such as the diameters of hydraulic lines, calibrated orifices and internal volumes, among others, are analysed. The objective of the study is to quantify the impact of small variations in the nominal value of these parameters on the injection rate profile for a given injector operating condition. In the case of the functional parameters, these small variations may be attributed to possible undesired fluctuations in the conditions that the injector is submitted to. As far as the geometrical and flow parameters are concerned, the small variations studied are representative of manufacturing tolerances that could influence the injected mass flow rate. As a result, it has been noticed that the configuration of the inlet and outlet orifices of the control volume, together with the discharge coefficient of the inlet orifice, among a few others, play a remarkable role in the injector performance. The reason resides in the fact that they are in charge of controlling the behaviour of the pressure in the control volume, which importantly influences injector dynamics and therefore the injection process. Variations of only 5% in the diameter of these orifices strongly modify the shape of the rate of injection curve, influencing both the injection delay and the duration of the injection process, consequently changing the total mass delivered.

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Critical Conditions and the Choking Mass Flow Rate in Nonequilibrium Wet Steam Flows

Journal of Fluids Engineering ◽

10.1115/1.3243146 ◽

1984 ◽

Vol 106 (4) ◽

pp. 452-458 ◽

Cited By ~ 8

Author(s):

J. B. Young

Keyword(s):

Mass Flow Rate ◽

Mass Flow ◽

Flow Rate ◽

Speed Of Sound ◽

Back Pressure ◽

Critical Conditions ◽

Wet Steam ◽

One Dimensional ◽

Maximum Value ◽

Upstream Flow

A theoretical analysis of choking in steady, one-dimensional, nonequilibrium, wet steam flows is presented. It is shown that such a flow becomes choked when the vapor phase velocity attains the frozen speed of sound somewhere in the system. The upstream flow pattern cannot then be altered by small adjustments of the back pressure and the mass flow rate is close to, although not necessarily identical to, its maximum value. The equilibrium speed of sound has no physical relevance in such flows. In a choked converging nozzle the critical conditions always occur in the exit plane of the nozzle. In a converging-diverging nozzle, however, the shape of the diverging section influences the throat conditions and throughput. Comparison of the theory with the few experiments reported in the literature shows excellent agreement.

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NUMERICAL MODELLING OF HOMOGENEOUS TWO-PHASE GAS-LIQUID FLOW IN A PIPE

Jurnal Teknologi ◽

10.11113/jt.v77.6361 ◽

2015 ◽

Vol 77 (13) ◽

Author(s):

Ibrahim D. Yale ◽

Norsarahaida Amin

Keyword(s):

Mass Flow Rate ◽

Mass Flow ◽

Flow Rate ◽

Splitting Method ◽

Two Phase ◽

Mixture Flow ◽

One Dimensional ◽

Flow Problems ◽

Flux Vector Splitting ◽

Gas Liquid Flow

A one-dimensional model which represent a system of partial differential equations that describe mathematically the two-phase flow has been considered for the gas-liquid mixture flow in a pipeline. The Implicit Steger -Warming flux vector splitting method is used for the numerical computation on air-water compressible flow problems. The results for pressure wave propagation, celerity or speed of sound and mass flow rate for different values of mass ratio were obtained. It was observed that the propagation of pressure along the pipeline and the mass flow rate there decreases along the pipe and maintained near a steady flow until it reaches the downstream of the pipe signifying the effect of gas build up during the pump control in pipeline.

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An integral model for gas entrainment into full cone sprays

Journal of Fluid Mechanics ◽

10.1017/s0022112001004591 ◽

2001 ◽

Vol 439 ◽

pp. 353-366 ◽

Cited By ~ 28

Author(s):

G. E. COSSALI

Keyword(s):

Mass Flow Rate ◽

Mass Flow ◽

Flow Rate ◽

Droplet Diameter ◽

Integral Model ◽

Axial Distance ◽

One Dimensional ◽

Gas Entrainment ◽

Apparent Inconsistency ◽

Dimensional Parameters

The paper proposes a one-dimensional model for predicting gas entrainment into a non-evaporating full cone steady spray injected into a stagnant gas at uniform pressure. The main outcome is a law relating the entrained mass flow rate to injected mass flow rate, gas properties, mean droplet diameter and axial distance from the nozzle. A comparison with available experimental data is presented. The model allows the apparent inconsistency of the experimental results obtained under different conditions to be eliminated by identifying two new non-dimensional parameters.

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Measurement of Air Velocity Components of Natural Convective Interzonal Airflow

Journal of Solar Energy Engineering ◽

10.1115/1.3268217 ◽

1987 ◽

Vol 109 (4) ◽

pp. 267-273 ◽

Cited By ~ 1

Author(s):

Bal M. Mahajan

Keyword(s):

Mass Flow Rate ◽

Mass Flow ◽

Flow Rate ◽

Three Dimensional ◽

Test Facility ◽

National Bureau ◽

Dimensional Model ◽

Measured Velocity ◽

One Dimensional ◽

Proper Values

Recent flow visualization tests performed at the National Bureau of Standards Passive Solar Test Facility indicated that the natural convective interzonal flow through a doorway is three-dimensional with the velocity components perpendicular to the plane of the opening and the plane of the floor appearing dominant. In order to further investigate the velocity components of the interzonal airflow through a doorway, an experimental study was undertaken. A simple one-dimensional model is modified to apply to two-dimensional airflow. Empirical expressions for the X velocity component and interzonal mass flow rate are developed. The measured velocity and mass flow rate data and the resulting empirical expression are compared with the values predicted by the simple one-dimensional model. It is found that the natural convective interzonal airflow may be adequately represented by two one-dimensional equations, one for the outflow and a different one for the inflow, provided that proper values of the outflow and inflow discharge coefficients are known.

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