A New Method for Performance Measurement of PPV Fans for Fire Fighting Under Realistic Conditions

2020 ◽  
Author(s):  
Michael Steppert ◽  
Philipp Epple ◽  
Michael Steber ◽  
Stefan Gast
Keyword(s):  
Design Process ◽  
Flow Rate ◽  
Volumetric Flow Rate ◽  
Navier Stokes ◽  
Analytical Relation ◽  
Positive Pressure ◽  
Flow Rates ◽  
Free Jet ◽  
Actual Flow Rate ◽  
Coefficient Of Discharge

Abstract PPV Fans (Positive Pressure Ventilation Fans) are used in firefighting to remove smoke from a burning building, so that fire fighters can have a clear view inside the house and injured people do not have to breathe toxic smoke. This can be done by placing a PPV fan in a distance of about two meters in front of a door of the burning building. On another, carefully chosen position in the building, e. g. a window, a door or at the roof an opening has to be created, where the smoke can leave the building. The same volumetric flow rate of gas that is blown into the building by the PPV fan has to leave the building at a chosen opening. Because the gas entering the building is air and the gas leaving the building is a mixture of smoke and air, the smoke concentration in the building can be reduced. To test the performance of such PPV fans, a test building with a door in the first floor and a window in the 3rd floor has been built. To measure the volumetric flow rate of the smoke and air mixture through the window in the 3rd floor that is leaving the building, a flow meter nozzle was designed. The design process was done using the commercial Navier Stokes solver Star CCM+, where three nozzle designs, such as a nozzle with constant velocity increase, a quarter circle nozzle and a non-curved nozzle were investigated for different volumetric flow rates. Also, a rounding at the window, where the nozzle is placed, was investigated to prevent flow detachment and shock losses at the inlet of the nozzle. The volumetric flow rate through the nozzle can be calculated, by measuring the pressure at the nozzle wall (before the contraction) and applying Bernoulli’s law, the continuity equation and assuming atmospheric pressure at the free jet flow at the end of the nozzle. The so calculated volumetric flow rate was compared with the actual flow rate, given by the numerical CFD simulations. With these values, the nozzle specific coefficient of discharge for several volumetric flow rates has been calculated and a function fitting was done to get obtain analytical relation between pressure and volumetric flow rate. The detailed design process of the three nozzles, the numerical results of the CFD studies and the determination of the nozzle specific coefficients of discharge are shown and discussed in detail in this work.

Simultaneous Measuring Method for Both Volumetric Flow Rates of Air-Water Mixture Using a Turbine Flowmeter

1996 ◽  
Vol 118 (1) ◽  
pp. 29-35 ◽  
Author(s):  
K. Minemura ◽  
K. Egashira ◽  
K. Ihara ◽  
H. Furuta ◽  
K. Yamamoto
Keyword(s):  
Pressure Drop ◽  
Flow Rate ◽  
Volumetric Flow Rate ◽  
Oil Field ◽  
Liquid Density ◽  
Water Mixture ◽  
Rotor Speed ◽  
Flow Rates ◽  
Field Development ◽  
Turbine Flowmeter

A turbine flowmeter is employed in this study in connection with offshore oil field development, in order to measure simultaneously both the volumetric flow rates of air-water two-phase mixture. Though a conventional turbine flowmeter is generally used to measure the single-phase volumetric flow rate by obtaining the rotational rotor speed, the method proposed additionally reads the pressure drop across the meter. After the pressure drop and rotor speed measured are correlated as functions of the volumetric flow ratio of the air to the whole fluid and the total volumetric flow rate, both the flow rates are iteratively evaluated with the functions on the premise that the liquid density is known. The evaluated flow rates are confirmed to have adequate accuracy, and thus the applicability of the method to oil fields.

P4379Pathophysiology of left atrial filling in mitral regurgitation. A new volumetric flow rate index describing disturbed left atrial filling behavior in mitral regurgitation by 3D TTE

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
D Frumkin ◽  
K Stangl ◽  
A Muegge ◽  
T Buck ◽  
B Plicht
Keyword(s):  
Mitral Regurgitation ◽  
Left Atrium ◽  
Flow Rate ◽  
Left Atrial ◽  
Volume Overload ◽  
Volumetric Flow Rate ◽  
Left Ventricular ◽  
Left Ventricular Ejection ◽  
Mean Flow ◽  
Flow Rates

Abstract Background In chronic mitral regurgitation (MR) the left atrium (LA) is one of the first cardiac structures involved in remodeling by progressive volume overload. Real-time three-dimensional echocardiography is able to monitor volumetric changes of the left atrium during the heart cycle. Purpose We hypothesized that chronic volume overload due to MR leads to detectable changes in the LA filling behavior described by mean and maximum filling flow rates and their relation called volumetric flow rate index. Methods We prospectively analyzed data of 36 patients in different stages of chronic MR and 13 patients without MR. Transthoracic echocardiography was conducted using the Epiq 7G Ultrasound System. Standard 2D- and 3D apical 4-chamber views were recorded and stored for offline analysis. We generated volume-time-curves by 3D volume analysis to derive mean and maximum volumetric flow rates during LA reservoir, conduit and pump phase. Volumetric flow rate index was calculated as the quotient of mean flow rate/maximum flow rate. Results Average MR severity, calculated with the MR Scoring system introduced from Buck et al. and implicated in the ESC Guidelines, was 6.2 points (±2.5) according to Grade I-II. We included 13 patients without MR, 18 with mild MR, 12 patients with moderate MR, 6 patients with severe MR. Left ventricular ejection fraction was similar in the different groups (51,2±12,3%). Maximum and mean flow rate showed no significant correlation with MR severity. Correlation of MR severity with LA dilation (ml/m2 BSA) was r=0.41; p<0.001. Flow rate index showed strong significant correlation with MR severity in left atrial reservoir phase (r=−0.75; p<0.001). There was no statistically relevant difference of volumetric flow rate parameters in left atrial pump and conduit phase. Line chart Conclusions We observed a significant correlation of the volumetric flow rate index to MR severity in the left atrial reservoir phase with stronger correlation than MR severity to left atrial dilation. The results of this work encourage further investigations to establish the presented volumetric flow rate index as a progression marker of MR and to evaluate its prognostic value.

scholarly journals Influence of Pressure on Gas/Liquid Interfacial Area in a Tray Column

2020 ◽  
Vol 10 (13) ◽  
pp. 4617
Author(s):  
Adel Almoslh ◽  
Falah Alobaid ◽  
Christian Heinze ◽  
Bernd Epple
Keyword(s):  
Flow Rate ◽  
Gas Flow ◽  
Volumetric Flow Rate ◽  
Interfacial Area ◽  
Gas Flow Rate ◽  
Test Rig ◽  
Flow Rates ◽  
Waste Gas ◽  
Simulated Waste ◽  
Series Of Experiments

The influence of pressure on the gas/liquid interfacial area is investigated in the pressure range of 0.2–0.3 MPa by using a tray column test rig. A simulated waste gas, which consisted of 30% CO2 and 70% air, was used in this study. Distilled water was employed as an absorbent. The temperature of the inlet water was 19 °C. The inlet volumetric flow rate of water was 0.17 m3/h. Two series of experiments were performed; the first series was performed at inlet gas flow rate 15 Nm3/h, whereas the second series was at 20 Nm3/h of inlet gas flow rate. The results showed that the gas/liquid interfacial area decreases when the total pressure is increased. The effect of pressure on the gas/liquid interfacial area at high inlet volumetric gas flow rates is more significant than at low inlet volumetric gas flow rates. The authors studied the effect of decreasing the interfacial area on the performance of a tray column for CO2 capture.

Effect of the axial gap on the energy consumption of a single-blade wastewater pump

2020 ◽  
pp. 095765092092736
Author(s):  
Federico Caruso ◽  
Craig Meskell
Keyword(s):  
Energy Consumption ◽  
Power Consumption ◽  
Flow Rate ◽  
Volumetric Flow Rate ◽  
Energy Performance ◽  
Navier Stokes ◽  
Gap Size ◽  
Ansys Fluent ◽  
Outlet Pressure ◽  
Pressure Discharge

The effect of the axial gap on the energy consumption of a single-blade wastewater pump (Sulzer XFP PE-2 150E CB1.1) is assessed using unsteady Reynolds-averaged Navier–Stokes simulations with ANSYS Fluent. The numerical model was compared to experimental data with a nominal design configuration (i.e. gap size) to provide confidence in the modeling approach. The global performance of the pump was evaluated in terms of pressure-discharge, torque, and efficiency for a range of volumetric flow rates (110 m3ċh−1 to 254 m3ċh−1) and gap sizes (0.3 mm to 1.15 mm). While it is found that the power consumption at a given flow rate is reduced with increased gap, this is at the expense of a drop in outlet pressure, and hence the efficiency of the pump drops significantly. At the largest volumetric flow rate considered (254 m3ċh−1), the sensitivity of the efficiency to the gap size is −13.5%ċmm−1 and the sensitivity of the reduction in mechanical power consumption to gap size is 0.58 kWċmm−1. These results emphasize the importance of active maintenance during the lifetime of a wastewater pump to avoid a reduction in the energy performance caused by increased gap size.

Experimental Investigation of Spray Cooling Heat Transfer on Circular Grooved Surface

2017 ◽  
Author(s):  
Azzam S. Salman ◽  
Jamil A. Khan
Keyword(s):  
Heat Transfer ◽  
Flow Rate ◽  
Cooling System ◽  
Volumetric Flow Rate ◽  
Target Surface ◽  
Spray Cooling ◽  
Operating Conditions ◽  
Low Flow ◽  
Inlet Temperature ◽  
Flow Rates

An experimental study was conducted in a closed loop spray cooling system working with deionized water as a cooling medium, to investigate the effects of surface modification on the spray cooling heat transfer enhancement in the single-phase region. Plain copper surface with diameter 1.5 cm and an enhanced surface with circular grooves were tested under different operating conditions. The volumetric flow rate of the coolant ranged from 115 mL/min to 177 mL/min., and the water inlet temperature was kept between 21–23 °C. Also, the distances between the nozzle and the target surface were varied at 8, 10, and 12 mm respectively. The results show that the distance between the nozzle and the target surface did not have a significant effect on the heat transfer performance for the low flow rates, while it has a slight effect on high flow rates for both surfaces. Also, increasing the liquid volumetric flow rate increases the amount of heat removed, and the heat transfer coefficient for both surfaces. Moreover, the maximum enhancement ratios achieved were 23.4% and 31% with volumetric flow rates of 153 mL/min, and 177 mL/min respectively.

High-performance aerosol sampler with liquid phase recirculation and pre-concentration of particles

2018 ◽  
pp. 25-31
Author(s):  
A. E. Akmalov ◽  
G. E. Kotkovskii ◽  
S. V. Stolyarov ◽  
B. I. Verdiev ◽  
R. S. Ovchinnikov ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Flow Rate ◽  
High Performance ◽  
Collection Efficiency ◽  
Volumetric Flow Rate ◽  
Flow Rates ◽  
Particle Collection ◽  
Aerosol Mass ◽  
Biogenic Aerosols ◽  
Short Time

Testing the surrounding environment for the presence of biogenic aerosols is crucial in ensuring its safety for the population. It is often necessary to collect aerosol samples from large areas in short time, which demands excellent particle collection efficiency, a sufficient incoming air flow rate and a capacity to maintain the viability of the collected samples. Below we present the aerosol sampler with a high volumetric flow rate based on a two-stage particle concentration algorithm and consisting of a virtual impactor and a cyclone concentrator with a recirculating liquid phase. We provide all necessary calculations and an algorithm for modeling impactor parameters. The sampler was tested using dry and liquid formulations dispersed into the particles of 0.5 to 5 μm in diameter. We demonstrate that at volumetric flow rates over 4,000 l/min efficiency of particle collection into the liquid phase at a volume of 10 ml makes over 20% of the total aerosol mass and at volumetric flow rates over 300 l/min this value is over 60%. The proposed device maintains viability of the collected microorganisms. The sampler is portable, with flexible settings for sampling and cleaning, and can be controlled remotely over the network.

New Design Method for Spiral Casings Considering the Properties of the Impeller and Spiral Casing at Design and Off-Design Conditions and Numerical Verification With CFD

2018 ◽  
Author(s):  
Philipp Epple ◽  
Manuel Fritsche ◽  
Michael Steppert ◽  
Michael Steber
Keyword(s):  
Design Process ◽  
Flow Rate ◽  
Velocity Component ◽  
Tangential Velocity ◽  
Sectional Area ◽  
Cross Sectional ◽  
Flow Rates ◽  
Tangential Velocity Component ◽  
Design Point ◽  
Spiral Casing

Radial fans for industrial applications are very commonly operated with a spiral casing, also called volute. The function of the volute is to collect the air from the impellers outlet and to transport it to the fans outlet. In the volute the tangential velocity component of the impeller is transformed in a straight velocity component at the volute’s outlet. In the volute the static pressure is increased according to the cross sectional area of the volute. When the flow exits the impeller the flow rate is given basically by the radial velocity component times the outlet area of the impeller. In the volute, however, the flow rate is basically given by the tangential velocity component at the impeller exit and in the volute considering the conservation of angular momentum. Hence, there is only one operating point, i.e. the design point of the volute, where the flow rate in the impeller matches the flow rate in the volute. In the literature the design of the volute is performed at the design point only and the cross sectional area of the volute is usually computed distributing the flow rate linearly from the tongue to the exit of the volute. In this work an extended theoretical approach was developed considering the design point flow rate and off design flow rates. At the design point, the properties of the specific impeller, i.e. it’s radial and its tangential velocity components at the impeller’s exit are considered to design the volute. Furthermore, also the off-design characteristics of the impeller, i.e. its radial and tangential velocity components are considered in the design process of the volute. The flow rates in the impeller and in the volute match only at the design point, at off-design points the flow rates in the impeller and in the volute are different. This has an important impact on the design process of impeller – volute units. Each volute has also to be matched to the specific impeller. In the numerical part a usual volute was designed considering the properties of a particular impeller. The performance of the volute and of complete fan was investigated with the commercial Navier–Stokes Solver ANSYS CFX. A detailed analysis of the results and the flow conditions in volute as well as in the impeller-volute unit and a comparison with the results predicted by the new volute theory is given.

scholarly journals High Flow-Rate Sample Loading in Large Volume Whole Water Organic Trace Analysis Using Positive Pressure and Finely Ground Sand as a SPE-Column In-Line Filter

Molecules ◽  
2019 ◽  
Vol 24 (7) ◽  
pp. 1426
Author(s):  
Ola Svahn ◽  
Erland Björklund
Keyword(s):  
Physicochemical Properties ◽  
Flow Rate ◽  
Solid Phase ◽  
Pure Water ◽  
Maximum Flow ◽  
Maximum Flow Rate ◽  
Positive Pressure ◽  
Flow Rates ◽  
Relative Standard ◽  
Whole Water

By using an innovative, positive pressure sample loading technique in combination with an in-line filter of finely ground sand the bottleneck of solid phase extraction (SPE) can be reduced. Recently published work by us has shown the proof of concept of the technique. In this work, emphasis is put on the SPE flow rate and method validation for 26 compounds of emerging environmental concern, mainly from the 1st and 2nd EU Watch List, with various physicochemical properties. The mean absolute recoveries in % and relative standard deviations (RSD) in % for the investigated compounds from spiked pure water samples at the three investigated flow rates of 10, 20, and 40 mL/min were 63.2% (3.2%), 66.9% (3.3%), and 69.0% (4.0%), respectively. All three flow rates produced highly repeatable results, and this allowed a flow rate increase of up to 40 mL/min for a 200 mg, 6 mL, reversed phase SPE cartridge without compromising the recoveries. This figure is more than four times the maximum flow rate recommended by manufacturers. It was indicated that some compounds, especially pronounced for the investigated macrolide molecules, might suffer when long contact times with the sample glass bottle occurs. A reduced contact time somewhat decreases this complication. A very good repeatability also held true for experiments on both spiked matrix-rich pond water (high and low concentrations) and recipient waters (river and wastewater) applying 40 mL/min. This work has shown that, for a large number of compounds of widely differing physicochemical properties, there is a generous flow rate window from 10 to 40 mL/min where sample loading can be conducted. A sample volume of 0.5 L, which at the recommended maximum flow rate speed of 10 mL/min, would previously take 50 min, can now be processed in 12 min using a flow rate of 40 mL/min. This saves 38 min per processed sample. This low-cost technology allows the sample to be transferred to the SPE-column, closer to the sample location and by the person taking the sample. This further means that only the sample cartridge would need to be sent to the laboratory, instead of the whole water sample, like today’s procedure.

scholarly journals Modeling of a controlled flow cup for improved transitional drinking development in children

2021 ◽  
Vol 8 ◽  
pp. 205566832110087
Author(s):  
Michael M Bailey-Van Kuren ◽  
Donna Scarborough
Keyword(s):  
Flow Rate ◽  
Volumetric Flow Rate ◽  
Swallowing Disorders ◽  
Design Tool ◽  
Liquid Volume ◽  
System Control ◽  
Flow Rates ◽  
Controlled Flow ◽  
Fast Flow ◽  
Cup Design

Introduction Clinical observations of children with swallowing disorders using a traditional “sippy” or transitional drinking cup identified a need for a novel cup. Children with swallowing disorders are often unable to initiate the forces required to activate the cup and/or maintain suction pressure. Furthermore, fast flow rates can result in choking. Methods A new cup design tool is proposed using fluid-cup interactions to capture the changing geometry of the fluid during drinking. A Petri net formulation is integrated with standard fluid flow principles. A new parametric cup simulation provides visualization and direct implementation for microcontroller prototypes. A vent-based controller is developed and modeled for a novel transitional drinking cup design. A simulated pouring study is performed for water and a baseline liquid volume of 200 ml in the cup. The study varies rotation rates, initial volume, system control and desired flow rates. Results Volumetric flow rate curves over time are generated and compared in relation to a target flow rate. The simulation results show expected behavior for variations in cup parameters. Conclusion The new simulation model facilitates future dysphagia research through rapid prototyping by tuning cup geometry, liquid parameters and control signals to meet the varying needs of the users.

Impact of flow rate on lactate uptake and gluconeogenesis in glucagon-stimulated perfused livers

2006 ◽  
Vol 290 (1) ◽  
pp. E185-E191 ◽  
Author(s):  
Ken D. Sumida ◽  
Jerry H. Urdiales ◽  
Casey M. Donovan
Keyword(s):  
Flow Rate ◽  
Dominant Role ◽  
Bicarbonate Buffer ◽  
Flow Rates ◽  
Exponential Decline ◽  
Actual Flow Rate ◽  
Actual Flow ◽  
Lactate Uptake ◽  
The Impact ◽  
Bovine Erythrocytes

The impact of reduced hepatic flow on lactate uptake and gluconeogenesis was examined in isolated glucagon-stimulated perfused livers from 24-h-fasted rats. After surgical isolation, livers were perfused (single pass) for 30 min with Krebs-Henseleit (KH) bicarbonate buffer, fresh bovine erythrocytes (hematocrit ∼20%), and no added substrate. After this “washout” period, steady-state perfusions were initiated with a second reservoir containing the KH buffer, bovine erythrocytes, [U-14C]lactate (10,000 dpm/ml), lactate (2.5 mM), and glucagon (250 μg/ml). Perfusion flow rate was adjusted to one of five rates (i.e., 1.8, 2.7, 3.9, 7.4, and 11.0 ml·min−1·100 g body wt−1). After the perfusion, the liver was dissected out and weighed so as to establish the actual flow rate per gram of liver. The resulting flow rates ranged from 0.52 to 4.03 ml·min−1·g liver−1. As a function of flow rate, lactate uptake rose in a hyperbolic fashion to an apparent plateau of 2.34 μmol·min−1·g liver−1. Fractional extraction (FX) of lactate from the perfusate demonstrated an exponential decline with increased flow rates ( r = 0.97). At flow rates above 1.0 ml·min−1·g liver−1, adjustments in FX compensated for changes in lactate delivery, resulting in steady rates of lactate uptake and gluconeogenesis. Below 1.0·min−1·g liver−1 the increased FX was unable to compensate for the decline in lactate delivery and lactate uptake declined rapidly. Gluconeogenesis demonstrated similar kinetics to lactate uptake, reflecting its dominant role among pathways for lactate removal under the current conditions.

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