Hydraulic characteristics of turbine impeller

1982 ◽  
Vol 47 (2) ◽  
pp. 421-429 ◽  
Author(s):  
Ivan Fořt ◽  
Jana Malá
Keyword(s):  
Mechanical Energy ◽  
Volumetric Flow Rate ◽  
Vessel Diameter ◽  
Diameter Ratio ◽  
Turbulent Regime ◽  
Hydraulic Efficiency ◽  
Hydraulic Characteristics ◽  
Total Head ◽  
Turbine Impeller

The study concentrates on the determination of hydraulic characteristics (volumetric flow rate, power output, hydraulic efficiency and total head) of a standard, six-blade turbine impeller in a flat-bottomed cylindrical vessel provided with radial baffles at a turbulent regime of agitated liquid. The investigated characteristics are determined by means of a macroscopic balance of mechanical energy of the impeller region expressed in a dimensionless form. The results show that all the hydraulic characteristics investigated, with the exception of the dimensionless impeller total head, are independent of the impeller-to-vessel diameter ratio. The hydraulic efficiency of a standard turbine impeller is about 40%.

Energetic efficiency of two impellers on the same shaft in a cylindrical baffled vessel of high height/diameter ratio

1989 ◽  
Vol 54 (9) ◽  
pp. 2345-2356 ◽  
Author(s):  
Ivan Fořt ◽  
Jiří Hájek ◽  
Václav Machoň
Keyword(s):  
High Speed ◽  
Power Input ◽  
Vessel Diameter ◽  
Diameter Ratio ◽  
Energetic Efficiency ◽  
Turbulent Regime ◽  
Inclined Plane ◽  
Pumping Effect ◽  
Charge Flow ◽  
Turbine Impeller

The paper deals with the experimental study of the indicating particle circulation and the impeller power input in a liquid mechanically agitated with two high-speed impellers (combination of the standard turbine impeller and the six inclined (at 45°) plane blades impeller) on the same shaft in a slender vessel (its height is equal double of the vessel diameter) equipped with four radial baffles at its walls under the turbulent regime of agitated charge flow. By the visual method of the indicating particle it is examined its circulation in the lower part of the system pumping effect of the lower impeller), its circulation in the upper part of the system (pumping effect of the upper impeller), and the exchangeable circulation between the upper and lower part of the system and vice versa. The impeller power input is ascertained from the measured current electricity in the anchor of the direct current driving motor. It follows from the calculated energetic efficiency (the ratio of the cube of the sum of the impeller flow rate numbers and the sum of the impeller power numbers) of the investigated combinations of impellers that the highest value of this quantity is exhibited for two standard turbine impellers on the same shaft and for a combination of the lower standard turbine impeller and the upper impeller with inclined plane blades pumping upwards; slightly less value of the impeller energetic efficiency appears for the combination of two impellers with six inclined plane blades, the upper one pumps liquid upwards and the lower one downwards. For all the configurations the vertical distance of impellers on the same shaft has to be longer than the vessel diameter.

Energy dissipation rate in a baffled vessel with pitched blade turbine impeller

1991 ◽  
Vol 56 (9) ◽  
pp. 1856-1867 ◽  
Author(s):  
Zdzisław Jaworski ◽  
Ivan Fořt
Keyword(s):  
Energy Dissipation ◽  
Cross Sections ◽  
Mechanical Energy ◽  
Vessel Diameter ◽  
Energy Dissipation Rate ◽  
Mean Velocity ◽  
Agitated Vessel ◽  
Radial Profiles ◽  
Pitched Blade Turbine ◽  
Turbine Impeller

Mechanical energy dissipation was investigated in a cylindrical, flat bottomed vessel with four radial baffles and the pitched blade turbine impeller of varied size. This study was based upon the experimental data on the hydrodynamics of the turbulent flow of water in an agitated vessel. They were gained by means of the three-holes Pitot tube technique for three impeller-to-vessel diameter ratio d/D = 1/3, 1/4 and 1/5. The experimental results obtained for two levels below and two levels above the impeller were used in the present study. Radial profiles of the mean velocity components, static and total pressures were presented for one of the levels. Local contribution to the axial transport of the agitated charge and energy was presented. Using the assumption of the axial symmetry of the flow field the volumetric flow rates were determined for the four horizontal cross-sections. Regions of positive and negative values of the total pressure of the liquid were indicated. Energy dissipation rates in various regions of the agitated vessel were estimated in the range from 0.2 to 6.0 of the average value for the whole vessel. Hydraulic impeller efficiency amounting to about 68% was obtained. The mechanical energy transferred by the impellers is dissipated in the following ways: 54% in the space below the impeller, 32% in the impeller region, 14% in the remaining part of the agitated liquid.

scholarly journals Study of the Blending Efficiency of Pitched Blade Impellers

10.14311/276 ◽  
2001 ◽  
Vol 41 (6) ◽  
Author(s):  
I. Fořt ◽  
T. Jirout ◽  
F. Rieger ◽  
R. Allner ◽  
R. Sperling
Keyword(s):  
Pitch Angle ◽  
Theoretical Data ◽  
Vessel Diameter ◽  
Diameter Ratio ◽  
Energetic Efficiency ◽  
Turbulent Regime ◽  
Conductivity Method ◽  
Homogenization Time ◽  
Miscible Liquids ◽  
The Given

This paper presents an analysis of the blending efficiency of pitched blade impellers under a turbulent regime of flow of an agitated low viscous liquid. The conductivity method is used to determine of the blending (homogenization) time of miscible liquids in pilot plant mixing equipment with standard radial baffles. For the given homogeneity degree (98 %) a three-blade pitched blade impeller is tested with various off-bottom clearances, vessel/ impeller diameter ratios and various impeller pitch angles. The experimental results show in accordance with theoretical data from the literature, that the greatest effect on the dimensionless blending time is exhibited by the vessel/ impeller diameter ratio and the impeller pitch angle. The number of total circulations necessary for reaching the chosen homogeneity degree depends on the impeller pitch angle and amounts more than three. Finally, the energetic efficiency of the blending process is calculated. The results of this study show, that the highest energetic efficiency of the three-blade pitched blade impeller appears for the pitch angle a = 24°, the impeller/vessel diameter ratio T/D = 2 and the impeller off-bottom clearance h/D = 1.

The flow of liquid in a stream from the standard turbine impeller

1979 ◽  
Vol 44 (3) ◽  
pp. 700-710 ◽  
Author(s):  
Ivan Fořt ◽  
Hans-Otto Möckel ◽  
Jan Drbohlav ◽  
Miroslav Hrach
Keyword(s):  
Reynolds Number ◽  
Kinematic Viscosity ◽  
Momentum Flux ◽  
Relative Size ◽  
Mean Velocity ◽  
Axial Profile ◽  
The Mean ◽  
Hot Film ◽  
Turbine Impeller

Profiles of the mean velocity have been analyzed in the stream streaking from the region of rotating standard six-blade disc turbine impeller. The profiles were obtained experimentally using a hot film thermoanemometer probe. The results of the analysis is the determination of the effect of relative size of the impeller and vessel and the kinematic viscosity of the charge on three parameters of the axial profile of the mean velocity in the examined stream. No significant change of the parameter of width of the examined stream and the momentum flux in the stream has been found in the range of parameters d/D ##m <0.25; 0.50> and the Reynolds number for mixing ReM ##m <2.90 . 101; 1 . 105>. However, a significant influence has been found of ReM (at negligible effect of d/D) on the size of the hypothetical source of motion - the radius of the tangential cylindrical jet - a. The proposed phenomenological model of the turbulent stream in region of turbine impeller has been found adequate for values of ReM exceeding 1.0 . 103.

Velocity Profiles of Liquid Flow Through Circular Tubes and How They Affect Flow Measurement

1991 ◽  
Vol 113 (3) ◽  
pp. 206-210 ◽  
Author(s):  
D. Yogi Goswami
Keyword(s):  
Transition Region ◽  
Laser Doppler Velocimetry ◽  
Flow Measurement ◽  
Velocity Profiles ◽  
Turbulent Regime ◽  
Flow Meters ◽  
Circular Tubes ◽  
Flow Through ◽  
Hydrogen Bubble Technique

This paper analyzes velocity profiles for flow through circular tubes in laminar, turbulent, and transition region flows and how they affect measurement by flow-meters. Experimental measurements of velocity profiles across the cross-section of straight circular tubes were made using laser doppler velocimetry. In addition, flow visualization was done using the hydrogen bubble technique. Velocity profiles in the laminar and the turbulent flow are quite predictable which allow the determination of meter factors for accurate flow measurement. However, the profiles can not be predicted at all in the transition region. Therefore, for the accuracy of the flowmeter, it must be ensured that the flow is completely in the laminar regime or completely in the turbulent regime. In the laminar flow a bend, even at a large distance, affects the meter factor. The paper also discusses some strategies to restructure the flow to avoid the transition region.

scholarly journals Mechanical energy storage performance of an aluminum fumarate metal–organic framework

2016 ◽  
Vol 7 (1) ◽  
pp. 446-450 ◽  
Author(s):  
Pascal G. Yot ◽  
Louis Vanduyfhuys ◽  
Elsa Alvarez ◽  
Julien Rodriguez ◽  
Jean-Paul Itié ◽  
...  
Keyword(s):  
Energy Storage ◽  
Mechanical Energy ◽  
Metal Organic Framework ◽  
Storage Performance ◽  
Metal Organic ◽  
Organic Framework

Determination of the mechanical energy storage performance of the aluminum fumarate metal–organic framework A520.

scholarly journals Study of Pumping Capacity of Pitched Blade Impellers

10.14311/380 ◽  
2002 ◽  
Vol 42 (4) ◽  
Author(s):  
I. Fořt ◽  
T. Jirout ◽  
R. Sperling ◽  
S. Jambere ◽  
F. Rieger
Keyword(s):  
Laser Doppler Anemometry ◽  
Radial Profile ◽  
Axial Flow ◽  
Power Input ◽  
Vessel Diameter ◽  
Energetic Efficiency ◽  
Turbulent Regime ◽  
Flat Bottom ◽  
Mean Velocity ◽  
Liquid Suspensions

A study was made of the pumping capacity of pitched blade impellers in a cylindrical pilot plant vessel with four standard radial baffles at the wall under a turbulent regime of flow. The pumping capacity was calculated from the radial profile of the axial flow, under the assumption of axial symmetry of the discharge flow. The mean velocity was measured using laser Doppler anemometry in a transparent vessel of diameter T = 400 mm, provided with a standard dished bottom. Three and six blade pitched blade impellers (the pitch angle varied within the interval a Îá24°; 45°ń) of impeller/vessel diameter ratio D/T = 0.36, as well as a three blade pitched blade impeller with folded blades of the same diameter, were tested. The calculated results were compared with the results of experiments mentioned in the literature, above all in cylindrical vessels with a flat bottom. Both arrangements of the agitated system were described by the impeller energetic efficiency, i.e, a criterion including in dimensionless form both the impeller energy consumption (impeller power input) and the impeller pumping effect (impeller pumping capacity). It follows from the results obtained with various geometrical configurations that the energetic efficiency of pitched blade impellers is significantly lower for configurations suitable for mixing solid-liquid suspensions (low impeller off bottom clearances) than for blending miscible liquids in mixing (higher impeller off bottom clearances).

scholarly journals The Relativistic and the Hidden Momentum of Minkowski and Abraham in Relativistic Energy Wave

2021 ◽  
Author(s):  
Daniel Cardoso
Keyword(s):  
Angular Momentum ◽  
Orbital Angular Momentum ◽  
Mechanical Energy ◽  
Recent Theory ◽  
Translational Energy ◽  
Angle Of Incidence ◽  
Relativistic Energy ◽  
Conservation Of Energy ◽  
Ignition Device

An analysis of the consistency of the Abraham and Minkowski momenta in the determination of the photon trajectory was carried out considering a new principle of conservation of the photon's mechanical energy, in which the photon conserves translational energy in orbital angular momentum when transiting between two media, introducing the relativistic energy wave (REW). The confrontation between REW and the recent theory of space-time waves (ST) was considered, pondering your differences. Throughout this study it was possible to verify that the Abraham momentum appears a relativistic photon ignition device in the transition between two media, acting as the hidden momentum of the Minkowski&rsquo;s relativistic momentum. The wavy behavior in the matter is relativistic, and the relativistic trajectory appears with delays and advances, with points of synchronization between source-observer. The classical or relativistic trajectories are determined as a function of the angle of incidence and the relative refractive index, by one of two distinct non-additive torques, the classic by Abraham or the relativistic by Minkowski. It was found that the same analysis conducted under the principle of conservation of the mechanical energy of the photon can be treated by an new Doppler, Relativistic Apparent, that can be confused with other Dopplers in the treatment of redshift from distant sources. It was found that the conservation of energy in Orbital Angular Momentum (OAM), in the interaction with matter, explains that the synchronization instants are found in the inversion of the OAM, where the advances and delays of REW occur under negligible variations of the OAM, however, opposites.

scholarly journals Dissipation of energy in the environment with turbulent viscosity and a Hill vortex

2019 ◽  
Vol 486 (6) ◽  
pp. 673-674
Author(s):  
G. F. Krymsky
Keyword(s):  
Shear Modulus ◽  
Mechanical Energy ◽  
Turbulent Viscosity ◽  
New Approach ◽  
Dissipation Of Energy

A new approach to calculation of the dissipation of mechanical energy in the environment with turbulent viscosity based on determination of the shear modulus of velocity is proposed. As an example the dynamics of Hill vortex moved in such environment is considered. The vortex radius extends linearly with the distance covered and makes up about 13% from it.

Sign in / Sign up

Export Citation Format

Share Document