Compressible Flow Ejectors: Part II—Flow Field Measurements and Analysis

1974 ◽  
Vol 96 (3) ◽  
pp. 282-288 ◽  
Author(s):  
K. R. Hedges ◽  
P. G. Hill
Keyword(s):  
Experimental Study ◽  
Mach Number ◽  
Mass Flow ◽  
Field Measurements ◽  
Flow Ratio ◽  
Flow Rates ◽  
Jet Mixing ◽  
Mass Flow Rates ◽  
Exit Mach Number ◽  
Mass Flow Ratio

An experimental study has been made of compressible jet mixing in an axisymmetric ejector of converging-diverging geometry. The mass flow ratio was in the range 1.3 to 2.6 and the nozzle exit Mach number was 1.82. Ejector performance characteristics were obtained as well as measurements of pressure and velocity distribution over a range of mass flow rates. The experimental results were used to test the reliability of the analytical model of the flow described in Part I of the paper.

Effect of nozzle angle, turbine inlets and mass flow rate on the performance of a bladeless turbine

2019 ◽  
Vol 234 (8) ◽  
pp. 1101-1107
Author(s):  
Muhammad Ali Kamran ◽  
Shahryar Manzoor
Keyword(s):  
Experimental Study ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Working Fluid ◽  
Operating Parameters ◽  
Lower Mass ◽  
Flow Rates ◽  
Significant Parameter ◽  
Mass Flow Rates

A comprehensive experimental study on the effects of different operating parameters on the efficiency of tesla turbine is reported. A bladeless turbine with nine discs and up to four turbine inlets was used, with water as the working fluid. The parameters investigated are the nozzle angle, number of turbine inlets and mass flow rates. Contrary to earlier studies, an effort was made to determine the performance under varying loading conditions, and hence identify the complete performance characteristics. The study revealed that efficiency of the turbine increases at lower nozzle angles and higher number of turbine inlets. It was observed that the nozzle angle becomes a significant parameter when the number of turbine inlets is increased. Efficiencies up to 78% were achieved when the working fluid entered the turbine through two nozzles at an angle of 7°. It was also noted that the turbine is most efficient at the designed mass flow rate, and the efficiency reduces appreciably if lower mass flow rates are fed to the turbine. The results obtained are an important contribution to the available knowledge and can be used as design references for further studies.

An Experimental Study of a “Once-Through” Thermosiphon System

1988 ◽  
Vol 110 (2) ◽  
pp. 90-97 ◽  
Author(s):  
R. Celentano ◽  
R. Kirchner
Keyword(s):  
Experimental Study ◽  
Mass Flow ◽  
Natural Circulation ◽  
Time Dependent ◽  
Circulation System ◽  
Outlet Temperature ◽  
Flow Rates ◽  
Mass Flow Rates ◽  
New Type ◽  
Mass Flows

An experimental study was conducted on the operation of a “once-through” thermosiphon system. This new type of natural circulation system, unlike the standard thermosiphon system, heats the collector fluid in one pass without any recirculation. An electrically heated manifold was used to simulate the useful solar gain. Power was varied with time in 22 half-hour increments to simulate the actual daily useful solar gain. The time-dependent responses of the system in terms of temperatures and mass flow rates were recorded and plotted. The response time for mass flow and temperature to approach steady state varied directly with the size of the power step. Two experiments were conducted; one which tracked mass flows and outlet temperatures for variable useful solar gains, and a second which tracked mass flows at constant outlet temperature for variable useful solar gains.

scholarly journals ŠILUMNEŠIO DEBITO ĮTAKOS FAZINIO VIRSMO MEDŽIAGOS VEIKIMUI TYRIMAS / INVESTIGATION OF THE INFLUENCE OF MASS FLOW RATE ON PHASE CHANGE MATERIAL BEHAVIOUR

2019 ◽  
Vol 11 (0) ◽  
pp. 1-5 ◽  
Author(s):  
Saulius Pakalka ◽  
Kęstutis Valančius ◽  
Matas Damonskis
Keyword(s):  
Experimental Study ◽  
Phase Change ◽  
Mass Flow Rate ◽  
Phase Change Material ◽  
Mass Flow ◽  
Flow Rate ◽  
Heat Transfer Fluid ◽  
Flow Rates ◽  
Mass Flow Rates ◽  
Change Material

The paper presents an experimental study of the influence of heat transfer fluid (HTF) mass flow rate on phase change materials (PCM) behaviour. The experimental study was performed on a specially designed test bench. Research object – PCM based thermal energy storage unit which consists of a stainless steel tank with dual circuit tube-fin copper heat exchanger. The tank (storage volume) was filled with phase change material RT82. The experiment was carried out using three different mass flow rates of HTF: high – 0.25 kg/s, medium – 0.125 kg/s, low – 0.05 kg/s. The analysis showed that in the case of high and medium mass flow rates the melting/solidification process highly depends on the temperature of inlet HTF. Influence of mass flow rate is higher in the case of low mass flow rate.

Experimental Study of the Diversion Crossflow Caused by Subchannel Blockages. Part I: Experimental Procedures and Mass Flow Rates in the Channels

1984 ◽  
Vol 106 (4) ◽  
pp. 435-440 ◽  
Author(s):  
S. Genc¸ay ◽  
A. Tapucu ◽  
N. Troche ◽  
M. Merilo
Keyword(s):  
Experimental Study ◽  
Mass Flow ◽  
Short Distance ◽  
Cross Flow ◽  
Geometric Parameters ◽  
Slow Process ◽  
Hydrodynamic Behavior ◽  
Flow Rates ◽  
Mass Flow Rates ◽  
Different Shapes

In this research, the hydrodynamic behavior of two laterally interconnected channels with blockages in one of them has been studied experimentally. For blockages of different shapes and severities, the mass flow rates as well as the pressures in the channels upstream and downstream of the blockage were determined. The experiments were conducted on a test sections which consists of two-square channels separated by an intermediate plate with slots of different geometric parameters. Two types of blockages have been considered: plate and smooth. The shape of the smooth blockage was a cosine. In the region upstream of the blockage, the diversion cross-flow takes place over a relatively short distance. Downstream of the blockage, the recovery of the diverted flow by the blocked channel is a slow process and the rate of this recovery worsens with increasing blockage severity. For a given blockage rate, the diversion crossflow caused by a smooth blockage is smaller than that of a plate blockage.

scholarly journals An experimental study of the mass flow rates effect on flat-plate solar water heater performance using Al2O3/water nanofluid

2017 ◽  
Vol 21 (suppl. 2) ◽  
pp. 379-388 ◽  
Author(s):  
Michael Prakasam ◽  
Thottipalayam Arjunan ◽  
Sadanandam Nataraj
Keyword(s):  
Experimental Study ◽  
Flat Plate ◽  
Mass Flow ◽  
Solar Water Heater ◽  
Water Heater ◽  
Flow Rates ◽  
Solar Water ◽  
Mass Flow Rates

scholarly journals Performance of a Turbine Airfoil With Multiple Film Cooling Stations: Part II — Aerodynamic Losses

1999 ◽  
Author(s):  
U. Drost ◽  
A. Bölcs
Keyword(s):  
Mach Number ◽  
Kinetic Energy ◽  
Mass Flow ◽  
Film Cooling ◽  
Momentum Flux ◽  
Density Ratio ◽  
Flux Ratio ◽  
Co2 Injection ◽  
Flow Rates ◽  
Mass Flow Rates

In the present study the aerodynamic performance of a turbine NGV airfoil was investigated, cooled from several showerhead, pressure and suction side stations. Film cooling heat transfer and effectiveness on this airfoil was examined in part I of this paper. Tests were conducted in a linear cascade at an exit Reynolds number of 1.45e6 and an exit Mach number 0.8. Density ratio effects were studied with air and CO2 injection, matching the densities by correctly adjusting the coolant temperature. In terms of a primary loss coefficient, neglecting the coolant kinetic energy, coolant injection increased the losses by 20–30% compared to solid blade losses, but depended only weakly on the coolant mass flow rate. A slight loss increase for increasing injection up to 2% coolant mass flow was noted, followed by a weak decrease for further augmented coolant mass flow rates. The primary losses appeared to be independent of the coolant medium and temperature. Thermodynamic loss coefficients including the loss of coolant kinetic energy, monotonically increased with coolant mass flow rates. To check the validity of CO2 injection for the simulation of high density ratios, the latter has been matched using strongly cooled air and heated CO2. The thermodynamic losses did not match at constant density ratio, but at constant coolant Mach number, when compared at constant coolant mass flow rates. Reporting the losses to the total pressure ratio (momentum flux ratio) yielded excellent scaling emphasizing the usefulness of the momentum flux ratio for film cooling loss scaling.

Experimental Study of the Diversion Crossflow Caused by Subchannel Blockages. Part II: Pressures in the Channels and the Comparison of the COBRA III-C Predictions With Experimental Data

1984 ◽  
Vol 106 (4) ◽  
pp. 441-447 ◽  
Author(s):  
A. Tapucu ◽  
S. Genc¸ay ◽  
N. Troche ◽  
M. Merilo
Keyword(s):  
Experimental Data ◽  
Experimental Study ◽  
Mass Flow ◽  
Geometric Parameters ◽  
Hydrodynamic Behavior ◽  
Flow Rates ◽  
Mass Flow Rates ◽  
Different Shapes ◽  
Plate Type

In this research, the hydrodynamic behavior of two laterally interconnected channels with blockages in one of them has been studied experimentally. For blockages of different shapes and severities, the mass flow rates as well as the pressures in the channels upstream and downstream of the blockage were determined. The experiments were conducted on two square channels separated by an intermediate plate with slots of different geometric parameters. Two types of blockages have been considered: plate and smooth. The shape of the smooth blockage was a cosine. The experimental data on the mass flow rates and pressures in the channels have been compared with the predictions of the subchannel code COBRA-III-C. It is observed that COBRA-III-C may not be adequate to describe the hydrodynamic behavior of two-interconnected channels with plate type blockages much higher than 30 percent severity in one of the channels. The limit of applicability of the code in the case of smooth blockages can be safely extended up to 60 percent severity.

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