Unsteady Interaction Between Annulus and Turbine Rim Seal Flows

2012 ◽  
Author(s):  
Martin Chilla ◽  
Howard Hodson ◽  
David Newman
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Gas Turbines ◽  
Measurement Data ◽  
Design Flow ◽  
Flow Conditions ◽  
Disc Space ◽  
Flow Interaction ◽  
The Impact

In core gas turbines relatively cold air is purged through the hub gap between stator and rotor in order to seal the disc space against flow ingestion from the main annulus. Although the sealing mass flow rate is commonly very small compared to the main annulus mass flow rate, it can have significant effects on the development of the passage endwall flows and on the overall loss generation. In this paper, the interaction between annulus and rim sealing flows is investigated using numerical simulations of a generic high-pressure turbine. At first, the numerical approach is validated by comparing the results of calculations to measurement data at the design flow conditions. Following that, results from steady and unsteady calculations are used to describe in detail the aerodynamics in overlap-type rim seals and their effects on the blade passage flow. It is found that the flow interaction at the rim seal interface is strongly influenced by the velocity deficit of the rim sealing flow relative to the annulus flow as well as by the circumferentially non-uniform pressure field imposed by the rotor blades. At typical sealing flow conditions, the flow interaction is found to be naturally unsteady, with periodical vortex shedding into the rotor passage. Finally, the influence of the specific rim seal shape on the flow unsteadiness at the rim seal interface is investigated and the impact on turbine performance is assessed.

Unsteady Interaction Between Annulus and Turbine Rim Seal Flows

2013 ◽  
Vol 135 (5) ◽  
Author(s):  
Martin Chilla ◽  
Howard Hodson ◽  
David Newman
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Gas Turbines ◽  
Measurement Data ◽  
Tangential Velocity ◽  
Numerical Approach ◽  
Design Flow ◽  
Flow Conditions ◽  
Flow Interaction

In core gas turbines relatively cold air is purged through the hub gap between the stator and rotor in order to seal the disk space against flow ingestion from the main annulus. Although the sealing mass flow rate is commonly very small compared to the main annulus mass flow rate, it can have significant effects on the development of the passage endwall flows and on the overall loss generation. In this paper, the interaction between the annulus and rim sealing flows is investigated using numerical simulations of a generic high-pressure turbine. At first, the numerical approach is validated by comparing the results of calculations to measurement data at the design flow conditions. Following that, results from steady and unsteady calculations are used to describe in detail the aerodynamics in overlap-type rim seals and their effects on the blade passage flow. It is found that the flow interaction at the rim seal interface is strongly influenced by the velocity deficit of the rim sealing flow relative to the annulus flow as well as by the circumferentially nonuniform pressure field imposed by the rotor blades. At typical sealing flow conditions, the flow interaction at the rim seal interface is found to be naturally unsteady, with periodical vortex shedding into the rotor passage. The rim seal geometry, in particular close to the annulus interface, is found to have an effect on the frequency of the shedding process. Finally, it is shown that the rim seal flow interaction can be stabilized by increasing either the sealing mass flow rate or the sealing tangential velocity.

Impact of Passive Tip-Injection on the Performance of Partially Shrouded Turbines: Basic Concept and Preliminary Results

2013 ◽  
Author(s):  
Pouya Ghaffari ◽  
Reinhard Willinger
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Gas Turbines ◽  
Turbine Blades ◽  
Tip Leakage Flow ◽  
Tip Leakage ◽  
Blade Tip ◽  
Tip Injection ◽  
The Impact

In terms of efficiency improvement many methods for reducing the blade tip-leakage mass flow rate have been proposed. Some of these methods are based on increasing the flow resistance with aid of geometrical modifications of the blade tip (squealers, winglets, shrouded blades, etc.) whereas other methods take advantage of aerodynamical resistance with passive tip-injection as an example. The objective of this paper is a combination of both methods in order to achieve higher reduction in tip-leakage mass flow rate. In the first part of this work necessary characteristic parameters of modern low pressure turbine blades in aircraft gas turbines are estimated. These parameters are taken into consideration to calculate the range of physical quantities influencing tip-leakage flow. Subsequently a two dimensional flow model is obtained with the so called discharge coefficient as the ratio of the actual tip gap mass flow rate to its highest possible value. The investigations are based on dimensionless calculations. In the end the results obtained from dimensionless 2D CFD-simulations are presented and compared with the analytical results. This leads to conclusions regarding the impact of various parameters on the effectiveness of the passive tip-injection.

Conjugate Heat Transfer Analysis on Generic Rim Seal Configurations in Rotor-Stator System

2018 ◽  
Author(s):  
Xingyun Jia ◽  
Liguo Wang ◽  
Qun Zheng ◽  
Hai Zhang ◽  
Yuting Jiang
Keyword(s):  
Heat Transfer ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Conjugate Heat Transfer ◽  
Heat Transfer Analysis ◽  
Minimum Mass ◽  
Aerodynamic Efficiency ◽  
Axial Clearance ◽  
The Impact

Performance of generic rim seal configurations, axial-clearance rim seal (ACS), radial-clearance rim seal (RCS), radial-axial clearance rim seal (RACS) are compared under realistic working conditions. Conjugate heat transfer analysis on rim seal is performed in this paper to understand the impact of ingestion on disc temperature. Results show that seal effectiveness and cooling effectiveness of RACS are the best when compared with ACS and RCS, the minimum mass flow rate for seal of RACS is 75% of that of RCS, and 34.6% of ACS. Authors compare the disc temperature distribution between different generic rim seal configurations where the RACS seems to be favorable in terms of low disc temperature. In addition, RACS has higher air-cooled aerodynamic efficiency, minimizing the mainstream performance penalty when compared with ACS and RCS. Corresponding to the respective minimum mass flow rate for seal, the air-cooled aerodynamic efficiency of RACS is 23.71% higher than that of ACS, and 12.79% higher than the RCS.

scholarly journals Performance investigation of a volute porous tongue of a turbocharger turbine

2020 ◽  
Vol 40 (1) ◽  
pp. 59-66
Author(s):  
Abderrahmane Chachoua ◽  
Mohamed Kamal Hamidou ◽  
Mohammed Hamel
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Gas Turbines ◽  
Stokes Equations ◽  
Navier Stokes ◽  
Recirculation Flow ◽  
Recirculating Flow ◽  
Show Evidence ◽  
The Right

The design for better performance of the spiral housing volute used commonly in radial and mixed inflow gas turbines is of prime importance as it affects the machine stage at both design and off design conditions. The tongue of the scroll divides the flow into two streams, and represents a severe source of disturbances, in terms of thermodynamic parameter uniformity, maximum kinetic energy, the right angle of attack to the rotor and minimum losses. Besides, the volute suffers an undesirable effect due to the recirculating mass flow rate in near bottom vicinity of the tongue. The present project is an attempt to design a tongue fitted with cylindrical holes traversing normal to the stream wise direction, where on account of the large pressure difference between the top and the bottom sides of the tongue will force the recirculating flow to go through the rotor inlet. This possibility with its limitations has not yet been explored. A numerical simulation is performed which might provide our suitable objectives. To achieve this goal the ANSYS code is used to build the geometry, generate the mesh, and to simulate the flow by solving numerically the averaged Navier Stokes equations. Apparently, the numerical results show evidence of favorable impact in using porous tongue. The realization of a contact between the main and recirculation flow by drilled holes on the tongue surface leads to a flow field uniformity, a reduction in the magnitude of the loss coefficient, and a 20 % reduction in the recirculating mass flow rate.

Design and Testing of a Can Combustor for a Small Gas Turbine Application

2013 ◽  
Author(s):  
K. V. L. Narayana Rao ◽  
N. Ravi Kumar ◽  
G. Ramesha ◽  
M. Devathathan
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Gas Turbines ◽  
Pressure Loss ◽  
High Energy ◽  
Experimental Results ◽  
High Mass ◽  
Test Facility ◽  
Design Requirements

Can type combustors are robust, with ease of design, manufacturing and testing. They are extensively used in industrial gas turbines and aero engines. This paper is mainly based on the work carried out in designing and testing a can type combustion chamber which is operated using JET-A1 fuel. Based on the design requirements, the combustor is designed, fabricated and tested. The experimental results are analysed and compared with the design requirements. The basic dimensions of the combustor, like casing diameter, liner diameter, liner length and liner hole distribution are estimated through a proprietary developed code. An axial flow air swirler with 8 vanes and vane angle of 45 degree is designed to create a re-circulation zone for stabilizing the flame. The Monarch 4.0 GPH fuel nozzle with a cone angle of 80 degree is used. The igniter used is a high energy igniter with ignition energy of 2J and 60 sparks per minute. The combustor is modelled, meshed and analysed using the commercially available ansys-cfx code. The geometry of the combustor is modified iteratively based on the CFD results to meet the design requirements such as pressure loss and pattern factor. The combustor is fabricated using Ni-75 sheet of 1 mm thickness. A small combustor test facility is established. The combustor rig is tested for 50 Hours. The experimental results showed a blow-out phenomenon while the mass flow rate through the combustor is increased beyond a limit. Further through CFD analysis one of the cause for early blow out is identified to be a high mass flow rate through the swirler. The swirler area is partially blocked and many configurations are analysed. The optimum configuration is selected based on the flame position in the primary zone. The change in swirler area is implemented in the test model and further testing is carried out. The experimental results showed that the blow-out limit of the combustor is increased to a good extent. Hence the effect of swirler flow rate on recirculation zone length and flame blow out is also studied and presented. The experimental results showed that the pressure loss and pattern factor are in agreement with the design requirements.

scholarly journals On-Sun Performance Evaluation of Alternative High-Temperature Falling Particle Receiver Designs

2018 ◽  
Vol 141 (1) ◽  
Author(s):  
Clifford K. Ho ◽  
Joshua M. Christian ◽  
Julius E. Yellowhair ◽  
Kenneth Armijo ◽  
William J. Kolb ◽  
...  
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Thermal Efficiency ◽  
Particle Temperature ◽  
Free Fall ◽  
Mass Flow Rates ◽  
Mesh Structures ◽  
Free Falling ◽  
The Impact

This paper evaluates the on-sun performance of a 1 MW falling particle receiver. Two particle receiver designs were investigated: obstructed flow particle receiver versus free-falling particle receiver. The intent of the tests was to investigate the impact of particle mass flow rate, irradiance, and particle temperature on the particle temperature rise and thermal efficiency of the receiver for each design. Results indicate that the obstructed flow design increased the residence time of the particles in the concentrated flux, thereby increasing the particle temperature and thermal efficiency for a given mass flow rate. The obstructions, a staggered array of chevron-shaped mesh structures, also provided more stability to the falling particles, which were prone to instabilities caused by convective currents in the free-fall design. Challenges encountered during the tests included nonuniform mass flow rates, wind impacts, and oxidation/deterioration of the mesh structures. Alternative materials, designs, and methods are presented to overcome these challenges.

Influence of Steam Injection on Thermal Efficiency and Operating Temperature of GE-F5 Gas Turbines Applying VODOLEY System

2005 ◽  
Author(s):  
Mohsen Ghazikhani ◽  
Nima Manshoori ◽  
Davood Tafazoli
Keyword(s):  
Power Plant ◽  
Ambient Temperature ◽  
Gas Turbine ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Thermal Efficiency ◽  
Gas Turbines ◽  
Steam Injection ◽  
Gas Turbine Cycle

An industrial gas turbine has the characteristic that turbine output decreases on hot summer days when electricity demand peaks. For GE-F5 gas turbines of Mashad Power Plant when ambient temperature increases 1° C, compressor outlet temperature increases 1.13° C and turbine exhaust temperature increases 2.5° C. Also air mass flow rate decreases about 0.6 kg/sec when ambient temperature increases 1° C, so it is revealed that variations are more due to decreasing in the efficiency of compressor and less due to reduction in mass flow rate of air as ambient temperature increases in constant power output. The cycle efficiency of these GE-F5 gas turbines reduces 3 percent with increasing 50° C of ambient temperature, also the fuel consumption increases as ambient temperature increases for constant turbine work. These are also because of reducing in the compressor efficiency in high temperature ambient. Steam injection in gas turbines is a way to prevent a loss in performance of gas turbines caused by high ambient temperature and has been used for many years. VODOLEY system is a steam injection system, which is known as a self-sufficient one in steam production. The amount of water vapor in combustion products will become regenerated in a contact condenser and after passing through a heat recovery boiler is injected in the transition piece after combustion chamber. In this paper the influence of steam injection in Mashad Power Plant GE-F5 gas turbine parameters, applying VODOLEY system, is being observed. Results show that in this turbine, the turbine inlet temperature (T3) decreases in a range of 5 percent to 11 percent depending on ambient temperature, so the operating parameters in a gas turbine cycle equipped with VODOLEY system in 40° C of ambient temperature is the same as simple gas turbine cycle in 10° C of ambient temperature. Results show that the thermal efficiency increases up to 10 percent, but Back-Work ratio increases in a range of 15 percent to 30 percent. Also results show that although VODOLEY system has water treatment cost but by using this system the running cost will reduce up to 27 percent.

Uncertainty Evaluation of the Natural Gas Molar Mass and Its Flow Rate Impact

2008 ◽  
Author(s):  
Elcio Cruz de Oliveira
Keyword(s):  
Natural Gas ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Molar Mass ◽  
Internal Diameter ◽  
Gas Measurement ◽  
Oil And Natural Gas ◽  
Mass Uncertainty ◽  
The Impact

In Brazil, the National Oil Agency — ANP and the National Metrology Institute elaborated Regulation No 1, on June 19th 2000. This government decree approves the Regulation of the Measurement Technique of Oil and Natural Gas, which establishes the minimum conditions and requirements for the oil and natural gas measurement systems, in order to guarantee accurate and complete results. The natural gas measurement fiscal systems must be projected, calibrated and operated so that the measurement uncertainty does not exceed 1.5%. Based on the norms AGA and ISO, the mathematical model for the calculation of the mass flow rate, depends on quantities that have well known uncertainty such as: orifice plate diameter, pipeline internal diameter, compressibility factor, discharge coefficient, differential pressure, static pressure and flow temperature. However, for the molar mass standard uncertainty fixed values are utilized in Brazil (mainly by IPT and PUC-RJ), around 0.30%, independent of the natural gas composition. The objective of this work is to develop a methodology to calculate the molar mass uncertainty of the natural gas derived from its chemical composition, analyzed by gaseous chromatography and to comparing it with the value currently practiced, evaluating the impact proceeding from this difference in the mass flow rate of the natural gas. Based on this methodology, the molar mass uncertainty is around 0.05% and the fiscal system uncertainty decreases in more than 10% when it is compared with the mass molar fixed value uncertainty.

scholarly journals Multiple Impinging Jet Air-Assisted Atomization

2017 ◽  
Author(s):  
Mário Costa ◽  
Bruno Pizziol ◽  
Miguel Panao ◽  
André Silva
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Alternative Fuels ◽  
Fossil Fuels ◽  
Cross Flow ◽  
Liquid Sheet ◽  
Air Mass ◽  
Breakup Mechanism ◽  
The Impact

The growth of the aviation sector triggered the search for alternative fuels and continued improvements in thecombustion process. This work addresses the technological challenges associated with spray systems and theconcern of mixing biofuels with fossil fuels to produce alternative and more ecological fuels for aviation. This workproposes a new injector design based on sprays produced from the simultaneous impact of multiple jets, using anadditional jet of air to assist the atomization process. The results evidence the ability to control the average dropsize through the air-mass flow rate. Depending on the air-mass flow rate there is a transition between atomizationby hydrodynamic breakup of the liquid sheet formed on the impact point, to an aerodynamic breakup mechanism,as found in the atomization of inclined jets under cross-flow conditions. The aerodynamic shear breakupdeteriorates the atomization performance, but within the same order of magnitude. Finally, our experiments showthat mixing a biofuel with a fossil fuel does not significantly alter the spray characteristics, regarded as a stepfurther in developing alternative and more ecological fuels for aero-engines.DOI: http://dx.doi.org/10.4995/ILASS2017.2017.4737

scholarly journals Importance of Communication in Law

2019 ◽  
Vol 8 (6S3) ◽  
pp. 1305-1307
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Diesel Fuel ◽  
Methyl Esters ◽  
Development Rate ◽  
Biodiesel Fuel ◽  
Gas Temperature ◽  
Warm Temperature ◽  
The Impact

The two horrible conditions ahead of time than the organizers worldwide are to diminish the stack at the conventional fills and to reduce the continually developing basic spoiling. This test is proposed to discover probably the execution of the DI diesel motor at various loads when fuelled with mixes of palm methyl esters and diesel. The primers have been pushed on a completely utilized diesel motor without changes. Every one of the appraisals were consistent usa of america and outfitted toward dependable pace. The impact of moving weight develop to be assessed the volume that brake warm temperature ability, mass flow rate, brake one of a kind gas use and fumes gas temperature. Exploratory impacts show that at complete weight conditions, the B-20, B-40and B-60 mixes bring 33.23%, 32.81%, 32.39% and 31.ninety seven% higher brake heat usefulness than sole diesel freely. It wound up confirmed that the brake warmth ability of palm biodiesel is higher than that of diesel, and it is a delayed consequence of the oxygenated atom of biodiesel which acknowledges total ingesting of the biodiesel fuel. In addition the mass development rate of biodiesel is evidently superior to anything that of diesel fuel; it is through method for exact capacity of the calorific estimation of biodiesel is a ton parcels less appeared in one another way as far as diesel gas. At the reason for results obtained from this test utilizing palm biodiesel as a fuel is proposed for the utilized as a piece of a diesel motor with diesel mixes.

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