Can-Annular Combustion Chamber Surface Temperature Measurements and Damage Signatures at Operationally Representative Conditions

2011 ◽  
Author(s):  
D. Bouchard ◽  
G. Pucher ◽  
W. D. E. Allan
Keyword(s):  
Surface Temperature ◽  
Combustion Chamber ◽  
Temperature Profile ◽  
Heat Exposure ◽  
Temperature Measurements ◽  
Experimental Program ◽  
Combustion Chambers ◽  
Excessive Heat ◽  
Exhaust Temperature ◽  
The Impact

An experimental program which investigated the surface temperature distribution of a contemporary gas turbine combustion liner is presented. An array of 65 embedded surface mounted thermocouples was installed on a Rolls Royce/Allison T56 combustion liner and exposed to combustion conditions in the Combustion Chamber Sector Rig (CCSR) at the Royal Military College of Canada. The CCSR was operated at two test points to simulate idle and cruise modes of operation. Corresponding exhaust temperature measurements were taken in the test combustion chamber exhaust plane with a sweeping thermocouple rake. These efforts were the latest in a multi-year program to investigate the impact of service wear related geometric deformations of combustion liners and damaged/fouled fuel nozzles on the exit temperature profile from typical combustion chambers. It has been previously ascertained that real-world geometric anomalies in the T56 combustion chambers, particularly in the transitional zone, can modify the exhaust temperature profile to a sufficient degree so as to risk hot section damage due to excessive heat exposure. The collection and analysis of surface temperature data represents a useful extension of the knowledge base of the T56 combustion system within the context of the overall program and is paramount to upcoming numerical modelling efforts aimed at assessing hot section damage risks.

scholarly journals Study on effect CO2 diluent on fuel cоmbustion in methane-oxygen combustion chambers

Vestnik IGEU ◽  
2021 ◽  
pp. 14-22
Author(s):  
I.I. Komarov ◽  
D.M. Kharlamova ◽  
A.N. Vegera ◽  
V.Y. Naumov
Keyword(s):  
Carbon Dioxide ◽  
Combustion Chamber ◽  
Combustion Process ◽  
Methane Combustion ◽  
Flame Stabilization ◽  
Total Carbon ◽  
Working Fluid ◽  
Combustion Mechanism ◽  
Combustion Chambers ◽  
The Impact

Studying closed gas turbine cycles on supercritical carbon dioxide is currently a promising issue in the development of power energy sector in terms of increasing energy efficiency and minimizing greenhouse gas emissions into the atmosphere. Combustion of methane with oxygen in the combustion chamber occurs not in the nitrogen environment, but in the environment of carbon dioxide, that is the working fluid of the cycle, which is an inhibitor of chemical reactions. A large mass content of such a diluent of the reaction mixture in the volume of the chamber leads to the risks of significant chemical underburning, efficiency decrease of the combustion chamber and the cycle as a whole. The aim of the research is to study the kinetic parameters of the combustion of methane with oxygen in a supercritical CO2 diluent medium to ensure reliable and stable combustion of fuel by assessing the degree of the inhibitory effect of CO2 and determining its permissible amount in the active combustion zone of the combustion chamber. The research method is a numerical simulation of turbulent-kinetic processes of methane combustion in the combustion chamber using the reduced methane combustion mechanism. Ansys Fluent software package has been used. The authers have studied the impact of CO2 diluent on fuel cоmbustion in methane-oxygen combustion chambers. It is found that the combustor flame stabilization takes place if the content of СО2 diluent supplied to the mixture with oxidizer is 0,46–0,5 of mass fraction; additional СО2 diluent forms local low temperature zones which slow down the combustion process. When this happens, adding cooling СО2 into the flame stabilization zone should be eliminated. The study has found that no more than 20 % of the total carbon dioxide content should be supplied to the combustion chamber; to stabilize the flame and reduce its length, it is necessary to install blades to swirl the fuel and oxidizer mixed with CO2 at the inlet of the combustion chamber; CO2 supply for cooling should be carried out not less than 130 mm away from the burner mouth.

Detection of Combustion Chamber Deposits in Diesel Engines Through Cylinder Pressure and Exhaust Temperature Measurements

2005 ◽  
Author(s):  
D. Gardiner ◽  
M. LaViolette ◽  
W. D. Allan ◽  
G. Wang ◽  
M. F. Bardon
Keyword(s):  
Combustion Chamber ◽  
Diesel Engines ◽  
Temperature Measurements ◽  
Cylinder Pressure ◽  
Clear Trend ◽  
Exhaust Temperature ◽  
Peak Heat Release Rate ◽  
Low Load ◽  
Combustion Chamber Deposits ◽  
Using Data

This paper describes experimental research aimed at developing techniques for monitoring the growth of combustion chamber deposits in diesel engines using data obtained from cylinder pressure and exhaust temperature measurements. A naturally aspirated single cylinder research engine was operated alternately between low load “coking” conditions (2.5 bar BMEP) and higher load “decoking” conditions (5.5 bar BMEP) intended to promote the formation and removal, respectively of combustion chamber deposits. The polytropic exponent of compression was observed to increase during coking runs and decrease during decoking runs. The peak heat release rate was observed to decrease during coking runs and increase during decoking runs. The peak cycle value of the first derivative of the exhaust thermocouple signal decreased during coking runs but exhibited no clear trend during decoking runs. Conventional exhaust temperature measurements showed no consistent trend during coking runs but the exhaust temperature decreased during decoking runs.

Time-Resolved Microscale Temperature Measurements of High-Power Semiconductor Lasers

2005 ◽  
Author(s):  
Paddy K. L. Chan ◽  
Amul D. Sathe ◽  
Kevin P. Pipe ◽  
Jason J. Plant ◽  
Paul W. Juodawlkis
Keyword(s):  
Surface Temperature ◽  
Temperature Profile ◽  
Semiconductor Lasers ◽  
High Power ◽  
Nondestructive Method ◽  
Temperature Measurements ◽  
Semiconductor Diode ◽  
Nonradiative Recombination ◽  
Time Resolved ◽  
Time Resolved Measurements

Nonradiative recombination and other heat generation processes affect both the performance and lifetime characteristics of semiconductor diode lasers. This is especially true for high-power devices, where facet heating due to nonradiative recombination can lead to catastrophic optical damage (COD). Here we present for the first time temperature measurements of a semiconductor laser in which the surface temperature profile (and hence the current density profile) of the laser is measured as it evolves in time. The laser studied is a λ=1.55μm 1-cm-long InGaAsP/InP watt-class slab-coupled optical waveguide laser (SCOWL). The ridge width of the SCOWLs examined here is approximately 5 μm. Temperature measurements are taken using multiple microthermocouples with sizes less than 20μm. Surface temperature fluctuations in time are seen to be quite large, as high as 20% of the total temperature increase of the device. Time-resolved measurements allow us to see both positive correlation (in which the temperature rises at the same time across an area of the device) as well as negative correlation (in which part of the device gets hot at the same time as another part of the device gets cold). Negative correlations are likely due to facet heating processes which cause bandgap shrinkage and hence increased current flow to a facet, pulling current away from the center of the device. Time-resolved measurements of the surface temperature profile therefore show promise as a nondestructive method for characterizing the failure mechanisms of a laser, as facet damage over time is otherwise very difficult to measure before the COD runaway process destroys the device.

scholarly journals Vostok (Antarctica) climate record time-scale deduced from the analysis of a borehole-temperature profile

1994 ◽  
Vol 20 ◽  
pp. 207-214 ◽  
Author(s):  
A.N. Salamatin ◽  
V.YA. Lipenkov ◽  
K.V. Blinov
Keyword(s):  
Surface Temperature ◽  
Temperature Profile ◽  
Time Scale ◽  
Ice Sheet ◽  
Temperature Measurements ◽  
Model Parameters ◽  
Measured Temperature ◽  
Time Curve ◽  
Temperature Variations ◽  
Climate Events

Several sets of temperature measurements were carried out in 1972- 88 in the Vostok boreholes. They have provided the ice-sheet temperature profile down to a depth of 2000 m. The accuracy of the profile is sufficient to analyze perturbations induced by the surface-temperature variations over the last climatic cycle. The mathematical model developed for the ice-temperature computation is applied to solve an inverse problem. The amplitudes and phase lags of the main harmonic components in the surface-temperature variations are reconstructed on the basis of fitting the calculated ice-temperature profile to the experimental one with the assumption that Milankovich's cycles (100, 41, 23 and 19 kyear) are dominant in the climate oscillations. The paleotemperature record simulated with the inverse procedure is revealed to be insensitive to the model parameters varied within the range of their uncertainty. Minimal standard deviation between calculated and measured temperature profiles is found of the same order as the reproducibility of the temperature measurements (0.005-0.01°C). Although the simulated temperature-time curve obtained in this study does not contain short-term variations, all the main climate events predicted from the ice-core isotope analysis can be recognized. Thus, the age of the events can be verified independently of the ice-sheet dynamics dating. The resultant time-scale for the Vostok record appears to be in good agreement with the dating of climate events recorded in deep-sea sediments.

Effects of Fuel Type on the Performance of Aero Gas Turbine Combustion Chambers, and the Influence of Design Features

1954 ◽  
Vol 58 (528) ◽  
pp. 813-825
Author(s):  
J. G. Sharp
Keyword(s):  
Combustion Chamber ◽  
Gas Turbine ◽  
Combustion Efficiency ◽  
Combustion Stability ◽  
Fuel Type ◽  
Combustion Chambers ◽  
Exhaust Temperature ◽  
Design Changes ◽  
Fuel Characteristics ◽  
Gas Turbine Combustion

SummaryThe performance of aero gas turbine combustion chambers is discussed under the following headings : Combustion efficiency, combustion stability, ease of ignition, deposits, exhaust temperature variation, and smooth combustion. It is shown that, as assessed by these criteria, combustion chamber performance can be significantly affected by fuel characteristics; also that the effects of fuel type can be greatly modified by equipment design changes. The conclusion is that most of the problems- aggravated by fuel characteristics are better solved by modifications to equipment, if fuel availability and cost are not to be adversely affected.

scholarly journals Vostok (Antarctica) climate record time-scale deduced from the analysis of a borehole-temperature profile

1994 ◽  
Vol 20 ◽  
pp. 207-214 ◽  
Author(s):  
A.N. Salamatin ◽  
V.YA. Lipenkov ◽  
K.V. Blinov
Keyword(s):  
Surface Temperature ◽  
Temperature Profile ◽  
Time Scale ◽  
Ice Sheet ◽  
Temperature Measurements ◽  
Model Parameters ◽  
Measured Temperature ◽  
Time Curve ◽  
Temperature Variations ◽  
Climate Events

Several sets of temperature measurements were carried out in 1972- 88 in the Vostok boreholes. They have provided the ice-sheet temperature profile down to a depth of 2000 m. The accuracy of the profile is sufficient to analyze perturbations induced by the surface-temperature variations over the last climatic cycle. The mathematical model developed for the ice-temperature computation is applied to solve an inverse problem. The amplitudes and phase lags of the main harmonic components in the surface-temperature variations are reconstructed on the basis of fitting the calculated ice-temperature profile to the experimental one with the assumption that Milankovich's cycles (100, 41, 23 and 19 kyear) are dominant in the climate oscillations. The paleotemperature record simulated with the inverse procedure is revealed to be insensitive to the model parameters varied within the range of their uncertainty. Minimal standard deviation between calculated and measured temperature profiles is found of the same order as the reproducibility of the temperature measurements (0.005-0.01°C). Although the simulated temperature-time curve obtained in this study does not contain short-term variations, all the main climate events predicted from the ice-core isotope analysis can be recognized. Thus, the age of the events can be verified independently of the ice-sheet dynamics dating. The resultant time-scale for the Vostok record appears to be in good agreement with the dating of climate events recorded in deep-sea sediments.

Impact of LULC Changes on LST in Rajshahi District of Bangladesh: A Remote Sensing Approach

2020 ◽  
Vol 3 (1) ◽  
pp. 11-23 ◽  
Author(s):  
Abdulla Al Kafy ◽  
Abdullah Al-Faisal ◽  
Mohammad Mahmudul Hasan ◽  
Md. Soumik Sikdar ◽  
Mohammad Hasib Hasan Khan ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Surface Temperature ◽  
Land Surface ◽  
Agricultural Land ◽  
Global Climate ◽  
Urban Expansion ◽  
Water Bodies ◽  
Landsat 8 ◽  
Lulc Changes ◽  
The Impact

Urbanization has been contributing more in global climate warming, with more than 50% of the population living in cities. Rapid population growth and change in land use / land cover (LULC) are closely linked. The transformation of LULC due to rapid urban expansion significantly affects the functions of biodiversity and ecosystems, as well as local and regional climates. Improper planning and uncontrolled management of LULC changes profoundly contribute to the rise of urban land surface temperature (LST). This study evaluates the impact of LULC changes on LST for 1997, 2007 and 2017 in the Rajshahi district (Bangladesh) using multi-temporal and multi-spectral Landsat 8 OLI and Landsat 5 TM satellite data sets. The analysis of LULC changes exposed a remarkable increase in the built-up areas and a significant decrease in the vegetation and agricultural land. The built-up area was increased almost double in last 20 years in the study area. The distribution of changes in LST shows that built-up areas recorded the highest temperature followed by bare land, vegetation and agricultural land and water bodies. The LULC-LST profiles also revealed the highest temperature in built-up areas and the lowest temperature in water bodies. In the last 20 years, LST was increased about 13ºC. The study demonstrates decrease in vegetation cover and increase in non-evaporating surfaces with significantly increases the surface temperature in the study area. Remote-sensing techniques were found one of the suitable techniques for rapid analysis of urban expansions and to identify the impact of urbanization on LST.

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