Adaptive High Precision Temperature Control of a Thermo-Mechanical Test Bench for Turbine Blades

2005 ◽  
Author(s):  
Michael Naderhirn ◽  
Luigi del Re
Keyword(s):  
Control Method ◽  
Mechanical Load ◽  
Mechanical Test ◽  
Technological Development ◽  
Turbine Blades ◽  
Essential Element ◽  
Large Temperature ◽  
Precision Temperature ◽  
High Control ◽  
Very High

Material testing is an essential element in the technological development of airplane turbines. The blades are subject to very high stresses, both thermal and mechanical. To assess material suitability, thermo-mechanical test benches are used where a typical thermo-mechanical load is applied to the test rigs. The sensitivity of the fatigue assessment is very high which requires a very high control precision over a large temperature range and a fast adaptation to different setups. This paper discusses two approaches where the first is a self tuning inverse control loop. The second approach is a data based control method where identification routines are used to dynamically compute the approximated system inverse and use this information to automatically tune the control system for saw-tooth profiles. It is shown that a simple two-zone thermal model describes the behavior of the probe and is then used to derive the inverse model and a control strategy. Finally experimental results of a typical test cycle are presented.

scholarly journals The Effect of Heat Transfer on Turbine Performance

2020 ◽  
Vol 142 (09) ◽  
pp. 56-57
Author(s):  
Lachlan J. Jardine ◽  
Robert J. Miller
Keyword(s):  
Heat Transfer ◽  
High Pressure ◽  
Gas Turbine ◽  
Turbine Blades ◽  
Large Temperature ◽  
Gas Turbine Blades ◽  
Turbine Performance ◽  
Very High

Abstract For over 50 years, high-pressure gas turbine blades have been cooled using air bled from the compressor. This cooling results in very high rates of heat transfer, both within the fluid and within the blade, shown in figure 1. The heat transfer often occurs across large temperature differences and is thus highly irreversible. It is therefore surprising that little is understood about the effect of this heat transfer on turbine performance.

Thermomechanical Fatigue Behavior of Bare and Coated CMSX-4

2009 ◽  
Vol 132 (1) ◽  
Author(s):  
T. Coppola ◽  
S. Riscifuli ◽  
O. Tassa ◽  
G. Pasquero
Keyword(s):  
Low Cycle Fatigue ◽  
Fatigue Behavior ◽  
Turbine Blades ◽  
Thermomechanical Fatigue ◽  
Tensile Creep ◽  
Thermal Gradients ◽  
Test Program ◽  
Complete Set ◽  
Comparison Of The Results ◽  
Very High

Highly cooled turbine blades undergo very high thermal gradients during rapid engine idle-max-idle cycling. Traditional isothermal fatigue data are often insufficient for predicting service lives. A complete set of high temperature tests, in the range of 750–1050°C, was performed on single crystal alloy CMSX-4. The test program comprised tensile, creep, low cycle fatigue, and thermomechanical fatigue (TMF) tests. In particular the cycle time for TMF was 3 min, aiming to simulate the real high-power transient conditions in aircraft engines. Clockwise and counterclockwise diamond cycle types were applied on bare and coated specimens to investigate their influence on the fatigue limit. The comparison of the results obtained with the available ones from open literature is discussed.

SUPPRESSING SPIRAL WAVES IN EXCITABLE MEDIA VIA UNIDIRECTIONAL COUPLING

2008 ◽  
Vol 22 (24) ◽  
pp. 4153-4161 ◽  
Author(s):  
YU QIAN ◽  
YU XUE ◽  
GUANG-ZHI CHEN
Keyword(s):  
Co Oxidation ◽  
Power Law ◽  
Coupling Strength ◽  
Control Method ◽  
Spiral Waves ◽  
Coupling Method ◽  
Excitable Media ◽  
Catalytic Co Oxidation ◽  
Unidirectional Coupling ◽  
High Control

A unidirectional coupling method to successfully suppress spiral waves in excitable media is proposed. It is shown that this control method has high control efficiency and is robust. It adapts to control of spiral waves for catalytic CO oxidation on platinum as well as for the FHN model. The power law n ~ c-k of control time steps n versus the coupling strength c for different models has been obtained.

scholarly journals Amorphous Silicon-Germanium Films with Embedded Nanocrystals for Thermal Detectors with Very High Sensitivity

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Cesar Calleja ◽  
Alfonso Torres ◽  
Pedro Rosales-Quintero ◽  
Mario Moreno
Keyword(s):  
Amorphous Silicon ◽  
Silicon Germanium ◽  
Chemical Vapor ◽  
Focal Plane Arrays ◽  
Large Temperature ◽  
Thermal Coefficient ◽  
Thermal Detectors ◽  
Germanium Films ◽  
Amorphous Silicon Germanium ◽  
Very High

We have optimized the deposition conditions of amorphous silicon-germanium films with embedded nanocrystals in a plasma enhanced chemical vapor deposition (PECVD) reactor, working at a standard frequency of 13.56 MHz. The objective was to produce films with very large Temperature Coefficient of Resistance (TCR), which is a signature of the sensitivity in thermal detectors (microbolometers). Morphological, electrical, and optical characterization were performed in the films, and we found optimal conditions for obtaining films with very high values of thermal coefficient of resistance (TCR = 7.9% K−1). Our results show that amorphous silicon-germanium films with embedded nanocrystals can be used as thermosensitive films in high performance infrared focal plane arrays (IRFPAs) used in commercial thermal cameras.

scholarly journals Environmental degradation of composites for marine structures: new materials and new applications

2016 ◽  
Vol 374 (2071) ◽  
pp. 20150272 ◽  
Author(s):  
Peter Davies
Keyword(s):  
Composite Materials ◽  
Test Data ◽  
Environmental Degradation ◽  
Structural Integrity ◽  
Mechanical Test ◽  
Traditional Approach ◽  
Essential Element ◽  
Structural Testing ◽  
Marine Structures

This paper describes the influence of seawater ageing on composites used in a range of marine structures, from boats to tidal turbines. Accounting for environmental degradation is an essential element in the multi-scale modelling of composite materials but it requires reliable test data input. The traditional approach to account for ageing effects, based on testing samples after immersion for different periods, is evolving towards coupled studies involving strong interactions between water diffusion and mechanical loading. These can provide a more realistic estimation of long-term behaviour but still require some form of acceleration if useful data, for 20 year lifetimes or more, are to be obtained in a reasonable time. In order to validate extrapolations from short to long times, it is essential to understand the degradation mechanisms, so both physico-chemical and mechanical test data are required. Examples of results from some current studies on more environmentally friendly materials including bio-sourced composites will be described first. Then a case study for renewable marine energy applications will be discussed. In both cases, studies were performed first on coupons at the material level, then during structural testing and analysis of large components, in order to evaluate their long-term behaviour. This article is part of the themed issue ‘Multiscale modelling of the structural integrity of composite materials’.

scholarly journals High Resolution Satellite Images for Instantaneous Shoreline Extraction Using New Enhancement Algorithms

Geosciences ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 123 ◽  
Author(s):  
Donatella Dominici ◽  
Sara Zollini ◽  
Maria Alicandro ◽  
Francesca Della Torre ◽  
Paolo Buscema ◽  
...  
Keyword(s):  
High Resolution ◽  
Large Scale ◽  
Satellite Images ◽  
Human Life ◽  
Essential Element ◽  
Action Planning ◽  
High Resolution Satellite Images ◽  
High Resolution Images ◽  
Territorial Government ◽  
Very High

Knowledge of a territory is an essential element in any future planning action and in appropriate territorial and environmental requalification action planning. The current large-scale availability of satellite data, thanks to very high resolution images, provides professional users in the environmental, urban planning, engineering, and territorial government sectors, in general, with large amounts of useful data with which to monitor the territory and cultural heritage. Italy is experiencing environmental emergencies, and coastal erosion is one of the greatest threats, not only to the Italian heritage and economy, but also to human life. The aim of this paper is to find a rapid way of identifying the instantaneous shoreline. This possibility could help government institutions such as regions, civil protection, etc., to analyze large areas of land quickly. The focus is on instantaneous shoreline extraction in Ortona (CH, Italy), without considering tides, using WorldView-2 satellite images (50-cm resolution in panchromatic and 2 m in multispectral). In particular, the main purpose of this paper is to compare commercial software and ACM filters to test their effectiveness.

scholarly journals Application of a logarithmic model on a stress - deformation interdependence of the recycled tires

2019 ◽  
Vol 13 (3) ◽  
pp. 180-183
Author(s):  
Anđelko Crnoja ◽  
Željko Kos ◽  
Oleg Popov
Keyword(s):  
Stress Resistance ◽  
Raw Materials ◽  
Technological Development ◽  
Tensile Force ◽  
High Accuracy ◽  
Specific Mass ◽  
Logarithmic Model ◽  
Independent Variables ◽  
Stress Deformation ◽  
Very High

During the last two decades, technological development has led to an extreme increase in transport and connected industries. This has significantly increased the production of automobile tires, which have their life span after which they go to waste. It is therefore necessary to extricate new products from recycled raw materials. For a product to be created, it is necessary, especially in civil engineering, to examine and determine all the properties of this material (pressure, traction, stress resistance, etc.). The results obtained by the research in this paper are mathematically processed by applying a logarithmic model. The aim of this process is to predict stress deformation in terms of tensile force. The model obtained is significant with accuracy of 87.21% and has a very high accuracy of the deformation estimation in relation to the applied stress. Independent variables were granulometric composition, binder (glue) and specific mass.

Collagen Fiber Re-Alignment and Mechanical Properties in a Mouse Supraspinatus Tendon Model: Examining Changes With Age and Location

2012 ◽  
Author(s):  
Kristin S. Miller ◽  
Brianne K. Connizzo ◽  
Elizabeth Feeney ◽  
Louis J. Soslowsky
Keyword(s):  
Mechanical Properties ◽  
Collagen Fiber ◽  
Mechanical Load ◽  
Mechanical Test ◽  
Insertion Site ◽  
Supraspinatus Tendon ◽  
Tissue Response ◽  
Mechanical Stimuli ◽  
Fiber Alignment ◽  
Collagen Fiber Alignment

One postulated mechanism of tendon structural response to mechanical load is collagen fiber re-alignment. Recently, where collagen fiber re-alignment occurs during a tensile mechanical test has been shown to vary by tendon age and location in a postnatal developmental mouse supraspinatus tendon (SST) model [1]. It is thought that as the tendon matures and its collagen fibril network, collagen cross-links and collagen-matrix interactions develop, its ability to respond quickly to mechanical stimuli hastens [1]. Additionally, the insertion site and midsubstance of postnatal SST may develop differently and at different rates, providing a potential explanation for differences in fiber re-alignment behaviors at the insertion site and midsubstance at postnatal developmental time points [1]. However, collagen fiber re-alignment behavior, in response to mechanical load at a mature age and in comparison to developmental ages, have not been examined. Therefore, the objectives of this study are to locally measure: 1) fiber re-alignment during preconditioning and tensile mechanical testing and 2) to compare local differences in collagen fiber alignment and corresponding mechanical properties to address tissue response to mechanical load in the mature and postnatal developmental mouse SST. We hypothesize that 1) 90 day tendons will demonstrate the largest shift in fiber re-alignment during preconditioning, but will also re-align during the toe- and linear-regions. Additionally, we hypothesize that 2) mechanical properties and initial collagen fiber alignment will be greater in the midsubstance of the tendon compared to the tendon-to-bone insertion site at 90 days, 3) that mechanical properties will increase with age, and that 4) collagen fiber organization at the insertion site will decrease with age.

scholarly journals Numerical Analysis of Wind Turbine Airfoil Aerodynamic Performance with Leading Edge Bump

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Majid Asli ◽  
Behnam Mashhadi Gholamali ◽  
Abolghasem Mesgarpour Tousi
Keyword(s):  
Wind Turbine ◽  
Control Method ◽  
Flow Behavior ◽  
Renewable Energy Sources ◽  
Lift Coefficient ◽  
Turbine Blades ◽  
Vortex Generator ◽  
Leading Edge ◽  
Suction Side ◽  
Aerodynamic Performance

Aerodynamic performance improvement of wind turbine blade is the key process to improve wind turbine performance in electricity generated and energy conversion in renewable energy sources concept. The flow behavior on wind turbine blades profile and the relevant phenomena like stall can be improved by some modifications. In the present paper, Humpback Whales flippers leading edge protuberances model as a novel passive stall control method was investigated on S809 as a thick airfoil. The airfoil was numerically analyzed by CFD method in Reynolds number of 106and aerodynamic coefficients in static angle of attacks were validated with the experimental data reported by Somers in NREL. Therefore, computational results for modified airfoil with sinusoidal wavy leading edge were presented. The results revealed that, at low angles of attacks before the stall region, lift coefficient decreases slightly rather than baseline model. However, the modified airfoil has a smooth stall trend while baseline airfoil lift coefficient decreases sharply due to the separation which occurred on suction side. According to the flow physics over the airfoils, leading edge bumps act as vortex generator so vortices containing high level of momentum make the flow remain attached to the surface of the airfoil at high angle of attack and prevent it from having a deep stall.

Film Cooling of Gas Turbine Blades: A Study of the Effect of Large Temperature Differences on Film Cooling Effectiveness

1977 ◽  
Vol 99 (1) ◽  
pp. 11-20 ◽  
Author(s):  
M. A. Paradis
Keyword(s):  
Gas Turbine ◽  
Film Cooling ◽  
Turbine Blades ◽  
Large Temperature ◽  
Constant Property ◽  
Cooling Effectiveness ◽  
Film Cooling Effectiveness ◽  
Gas Turbine Blades ◽  
Combustion Gases ◽  
Simple Equations

Experiments have been performed on the film cooling of gas turbine blades in order to study the influence of large temperature differences on the effectiveness of film cooling. A two-dimensional flat plate model was tested in a stream of 1000 K combustion gases flowing at between 110 and 170 m/s. The model was cooled on both sides by jets of air coming from flush angled slots. The range of velocity ratios Uc/Ug covered was from 0.3 to 1.7 and the range of blowing rates was between 0.5 and 5. Film cooling effectiveness was measured and boundary layer traverses were performed. It has been found that once radiation and conduction effects are taken into account, the simple equations proposed by previous workers for the constant property case could be used with little error.

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