scholarly journals Observation and Analysis of Affinity Law Deviations through Tested Performance of Liquefied Gas Reaction Turbines

2008 ◽  
Vol 2008 ◽  
pp. 1-5
Author(s):  
Sarah D. Alison-Youel
Keyword(s):  
Rotational Speed ◽  
Conservation Of Energy ◽  
Turbine Performance ◽  
General Performance ◽  
Hydrocarbon Gas ◽  
Relevant Field ◽  
Principal Application ◽  
Flow Head ◽  
Liquefied Gas ◽  
Performance Equation

Liquefied gas reaction turbines are subject to the hydraulic affinity laws. Particularly for liquefied hydrocarbon gas-driven turbines, deviations from the affinity laws are encountered. In the case of reaction turbines, where the geometry is fixed, the affinity law relationships between flow, head, and rotational speed are relevant. Field experience confirms that the affinity law relationships are adequate, but that the predictions made also tend to deviate from real turbine performance. Part of the deviations seen may be attributed to the nonideal fluid; however, further examination is warranted. This paper presents an investigation into the affinity law relationships between head, flow, and rotational speed in conjunction with actual turbine performance. The three basic affinity law relationships are combined to form the most general performance equation. This equation subsequently incorporates both the affinity law relationships and the conservation of energy principal. Application of real turbine test data shows that this general performance equation presents a more accurate representation of turbine performance than the affinity law relationships alone.

scholarly journals The Effect of Angle Variation in the Model V Blade on the Savonius-Type Vertical Axis Wind Turbine's Performance

2021 ◽  
Vol 328 ◽  
pp. 09005
Author(s):  
Witono Hardi ◽  
Zulkifli S. Tawary ◽  
Moh.Muzni Harbelubun
Keyword(s):  
Wind Speed ◽  
Experimental Method ◽  
Rotational Speed ◽  
Vertical Axis ◽  
Speed Ratio ◽  
Blade Angle ◽  
Angle Variation ◽  
Tip Speed Ratio ◽  
Turbine Efficiency ◽  
Turbine Performance

In this study, the researcher applied an experimental method to examine the performance of theSavonius-type turbine, in which variations in the blade angle were 85°, 95°, 105°, 110°, 115°, and 125°, variations in wind speed were 3 and 4.1 m/s, and variations in balancing force were 0.4 and 0.9 kg. The results showed that, of the five examined variations of the blade angle, the 125° blade produced the highest rotation (n) compared to the others. It generated 115.3 rpm but without a balanced force. Furthermore, the turbine performance at a wind speed (V) of 4.1 m/s, a balancing force (F) of 0.9 kg, and a blade angle of 125° produced the rotational speed (n) of 69.6 rpm, the turbine power (Pt) of 6.43 watts, the torque (T) of 1.765 N.m, the tip-speed ratio (λ) of 0.355, and the turbine efficiency 66.22%. Meanwhile, at a wind speed of 3 m/s, a balancing force (F) of 0.9 kg, and a blade angle of 125°, it generated the rotational speed (n) of 28.6 rpm, the turbine power (Pt) of 2.64 watts, the torque (T) of 1.765 N.m, the tip-speed ratio (λ) of 0.146, and the turbine efficiency 69.47%.

A Model for the Tool Temperature During Machining With a Rotary Tool

2001 ◽  
Author(s):  
Hossam A. Kishawy ◽  
Andrew G. Gerber
Keyword(s):  
Temperature Distribution ◽  
Rotational Speed ◽  
Measured Temperature ◽  
Tool Rotational Speed ◽  
Tool Temperature ◽  
Radial Temperature ◽  
Conservation Of Energy ◽  
Rotary Tool ◽  
Finite Volume Discretization ◽  
Heat Partitioning

Abstract In this paper a model is developed to analyze heat transfer and temperature distribution resulting during machining with rotary tools. The presented model is based on a finite-volume discretization approach applied to a general conservation of energy statement for the rotary tool and chip during machining. The tool rotational speed is modeled and its effect on the heat partitioning between the tool and the chip is investigated. The model is also used to examine the influence of tool speed on the radial temperature distribution on the tool rake face. A comparison between the predicted and previously measured temperature data shows good agreement. In general the results show that the tool-chip partitioning is influenced dramatically by increasing the tool rotational speed at low to moderate levels of tool speed. Also, there is an optimum tool rotational speed at which further increase in the tool rotational speed increases the average tool temperature.

Influence of Blade Deterioration on Compressor and Turbine Performance

2009 ◽  
Vol 132 (3) ◽  
Author(s):  
M. Morini ◽  
M. Pinelli ◽  
P. R. Spina ◽  
M. Venturini
Keyword(s):  
Gas Turbine ◽  
Rotational Speed ◽  
Mechanical Damage ◽  
Health State ◽  
Scaling Factors ◽  
Health Indices ◽  
Turbine Performance ◽  
Operating Region ◽  
State Determination ◽  
Simple Scaling

Gas turbine operating state determination consists of the assessment of the modification due to deterioration and fault of performance and geometric data characterizing machine components. One of the main effects of deterioration and fault is the modification of compressor and turbine performance maps. Since detailed information about actual modification of component maps is usually unavailable, many authors simulate the effects of deterioration and fault by a simple scaling of the map itself. In this paper, stage-by-stage models of the compressor and the turbine are used in order to assess the actual modification of compressor and turbine performance maps due to blade deterioration. The compressor is modeled by using generalized performance curves of each stage matched by means of a stage-stacking procedure. Each turbine stage is instead modeled as two nozzles, a fixed one (stator) and a moving one (rotor). The results obtained by simulating some of the most common causes of blade deterioration (i.e., compressor fouling, compressor mechanical damage, turbine fouling, and turbine erosion), occurring in one or more stages simultaneously, are reported in this paper. Moreover, compressor and turbine maps obtained through the stage-by-stage procedure are compared with the ones obtained by means of map scaling. The results show that the values of the scaling factors depend on the corrected rotational speed and on the load. However, since the variation in the scaling factors in the operating region close to the design corrected rotational speed is small, the use of the scaling factor as health indices can be considered acceptable for gas turbine health state determination at full load. Moreover, also the use of scaled maps in order to represent compressor and turbine behavior in deteriorated conditions close to the design corrected rotational speed can be considered acceptable.

Characteristics of Heat Transfer During Machining With Rotary Tools

2004 ◽  
Vol 126 (2) ◽  
pp. 404-407 ◽  
Author(s):  
H. A. Kishawy and ◽  
A. G. Gerber
Keyword(s):  
Heat Transfer ◽  
Temperature Distribution ◽  
Rotational Speed ◽  
Measured Temperature ◽  
Tool Rotational Speed ◽  
Radial Temperature ◽  
Conservation Of Energy ◽  
Finite Volume Discretization ◽  
Heat Partitioning ◽  
Good Agreement

In this paper a model is developed to analyze heat transfer and temperature distribution resulting during machining with rotary tools. The presented model is based on a finite-volume discretization approach applied to a general conservation of energy statement for the rotary tool and chip during machining. The tool rotational speed is modeled and its effect on the heat partitioning between the tool and the chip is investigated. The model is also used to examine the influence of tool speed on the radial temperature distribution on the tool rake face. A comparison between the predicted and previously measured temperature data shows good agreement. In general the results show that the tool-chip partitioning is influenced dramatically by increasing the tool rotational speed at low to moderate levels of tool speed. Also, there is an optimum tool rotational speed at which further increase in the tool rotational speed increases the average tool temperature.

scholarly journals Numerical and experimental characterization of splitter blade impact on pump as turbine performance

2021 ◽  
Vol 104 (2) ◽  
pp. 003685042199324
Author(s):  
Daniel Adu ◽  
Jianguo Du ◽  
Ransford O Darko ◽  
Eric Ofosu Antwi ◽  
Muhammad Aamir Shafique Khan
Keyword(s):  
Rotational Speed ◽  
Simulated Data ◽  
Maximum Deviation ◽  
Cfd Simulations ◽  
Flow Rates ◽  
Turbine Performance ◽  
Hydropower Dams ◽  
The Impact ◽  
Good Agreement

Several rivers and streams are available in Africa and Asian regions with great potentials not applicable for constructing large hydropower dams but feasible for small and mini hydro generation. This study strive for investigating the impact of splitter blade on pump as turbine performance considering different speed and flow rates. Two specific centrifugal pump models one with six blades without splitter and another with four blades and four splitters were used for the study. The inlet diameter and outlet diameters of both impellers were 104 mm/116 mm, and 160 mm respectively at a designed flow rate Q = 12.5 m3/h, head H = 16 m, rotational speed n = 1450 rpm and efficiency of 56%, outlet impeller width of 0.006 m, a blade outlet angle of 30° was used for the study. CFD simulations were conducted with the use of k-ε turbulence model. The influence of splitter blade position on the performance of pump as turbine in the selected specific pumps with and without splitter blades has been investigated both experimentally and numerically at three different flow rates and rotational speed. The simulated data were in good agreement with the experimental results, the maximum deviation error between the CFD and test for each model are 5.6%, 2.6%, for the head and efficiency; 7.5% and 3.6% at different flow conditions.

Redox Reactions in Lipid Membranes as a Model for Primordial Energy-Conserving Systems

1997 ◽  
Vol 161 ◽  
pp. 437-442
Author(s):  
Salvatore Di Bernardo ◽  
Romana Fato ◽  
Giorgio Lenaz
Keyword(s):  
Experimental Evidence ◽  
Lipid Membranes ◽  
Energy Supply ◽  
Redox Reactions ◽  
Living Systems ◽  
Asymmetric Distribution ◽  
Conservation Of Energy ◽  
Asymmetrical Distribution ◽  
Energy Conserving ◽  
Living Organisms

AbstractOne of the peculiar aspects of living systems is the production and conservation of energy. This aspect is provided by specialized organelles, such as the mitochondria and chloroplasts, in developed living organisms. In primordial systems lacking specialized enzymatic complexes the energy supply was probably bound to the generation and maintenance of an asymmetric distribution of charged molecules in compartmentalized systems. On the basis of experimental evidence, we suggest that lipophilic quinones were involved in the generation of this asymmetrical distribution of charges through vectorial redox reactions across lipid membranes.

New replica method with plasma polymerized film by glow discharge

1988 ◽  
Vol 46 ◽  
pp. 414-415
Author(s):  
A. Tanaka ◽  
M. Yamaguchi ◽  
T. Hirano
Keyword(s):  
Power Supply ◽  
Plasma Polymerization ◽  
Vacuum Chamber ◽  
Complex Surface ◽  
Replica Method ◽  
Metal Extraction ◽  
High Voltage Power Supply ◽  
Negative Glow ◽  
Hydrocarbon Gas ◽  
Hydrocarbon Molecules

The plasma polymerization replica method and its apparatus have been devised by Tanaka (1-3). We have published several reports on its application: surface replicas of biological and inorganic specimens, replicas of freeze-fractured tissues and metal-extraction replicas with immunocytochemical markers.The apparatus for plasma polymerization consists of a high voltage power supply, a vacuum chamber containing a hydrocarbon gas (naphthalene, methane, ethylene), and electrodes of an anode disk and a cathode of the specimen base. The surface replication by plasma polymerization in negative glow phase on the cathode was carried out by gassing at 0.05-0.1 Torr and glow discharging at 1.5-3 kV D.C. Ionized hydrocarbon molecules diffused into complex surface configurations and deposited as a three-dimensionally polymerized film of 1050 nm in thickness.The resulting film on the complex surface had uniform thickness and showed no granular texture. Since the film was chemically inert, resistant to heat and mecanically strong, it could be treated with almost any organic or inorganic solvents.

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