| 281. |
- Saha, Ranjan, et al.
(författare)
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Influence of pre-history and leading edge contouring on aero-performance of a 3D nozzle guide vane
- 2013
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Ingår i: Proceedings of the ASME Gas Turbine India Conference -2013- ; presented at ASME 2013 Gas Turbine India Conference, December 5-6, 2013, Bangalore, India. - : ASME Press.
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Konferensbidrag (refereegranskat)abstract
- Experiments are conducted to investigate the effect of the pre-history in the aerodynamic performance of a threedimensional nozzle guide vane with a hub leading edge contouring. The performance is determined with two pneumatic probes (5 hole and 3 hole) concentrating mainly on the endwall. The investigated vane is a geometrically similar gas turbine vane for the first stage with a reference exit Mach number of 0.9. Results are compared for the baseline and filleted cases for a wide range of operating exit Mach numbers from 0.5 to 0.9. The presented data includes loading distributions, loss distributions, fields of exit flow angles, velocity vector and vorticity contour, as well as, mass-averaged loss coefficients. The results show an insignificant influence of the leading edge fillet on the performance of the vane. However, the pre-history (inlet condition) affects significantly in the secondary loss. Additionally, an oil visualization technique yields information about the streamlines on the solid vane surface which allows identifying the locations of secondary flow vortices, stagnation line and saddle point.
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| 282. |
- Saha, Ranjan, 1984-, et al.
(författare)
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Influence of Prehistory and Leading Edge Contouring on Aero Performance of a Three-Dimensional Nozzle Guide Vane
- 2014
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Ingår i: Journal of turbomachinery. - : ASME Press. - 0889-504X .- 1528-8900. ; 136:7, s. 071014-1-071014-10
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Tidskriftsartikel (refereegranskat)abstract
- Experiments are conducted to investigate the effect of the prehistory in the aerodynamic performance of a three-dimensional nozzle guide vane with a hub leading edge contouring. The performance is determined with two pneumatic probes (five hole and three hole) concentrating mainly on the end wall. The investigated vane is a geometrically similar gas turbine vane for the first stage with a reference exit Mach number of 0.9. Results are compared for the baseline and filleted cases for a wide range of operating exit Mach numbers from 0.5 to 0.9. The presented data includes loading distributions, loss distributions, fields of exit flow angles, velocity vector, and vorticity contour, as well as mass-averaged loss coefficients. The results show an insignificant influence of the leading edge fillet on the performance of the vane. However, the prehistory (inlet condition) affects significantly in the secondary loss. Additionally, an oil visualization technique yields information about the streamlines on the solid vane surface, which allows identifying the locations of secondary flow vortices, stagnation line, and saddle point.
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| 283. |
- Saha, Ranjan, 1984-, et al.
(författare)
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Shower Head and Trailing Edge Cooling Influence on Transonic Vane Aero Performance
- 2014
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Ingår i: ASME Turbo Expo 2014. - : ASME Press. - 9780791845622
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Konferensbidrag (refereegranskat)abstract
- An experimental investigation on a cooled nozzle guide vane has been conducted in an annular sector to quantify aerodynamic influences of shower head and trailing edge cooling. The investigated vane is a typical high pressure gas turbine vane, geometrically similar to a real engine component, operated at a reference exit Mach number of 0.89. The investigations have been performed for various coolant-to-mainstream mass-flux ratios. New loss equations are derived and implemented regarding coolant aerodynamic losses. Results lead to a conclusion that both trailing edge cooling and shower head film cooling increase the aerodynamic loss compared to an uncooled case. In addition, the trailing edge cooling has higher aerodynamic loss compared to the shower head cooling. Secondary losses decrease with inserting shower head film cooling compared to the uncooled case. The trailing edge cooling appears to have less impact on the secondary loss compared to the shower head cooling. Area-averaged exit flow angles around midspan increase for the trailing edge cooling.
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| 284. |
- Saha, Ranjan, 1984-, et al.
(författare)
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Shower Head and Trailing Edge Cooling Influence on Transonic Vane Aero Performance
- 2014
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Ingår i: Journal of turbomachinery. - : ASME Press. - 0889-504X .- 1528-8900. ; 136:11, s. 111001-
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Tidskriftsartikel (refereegranskat)abstract
- An experimental investigation on a cooled nozzle guide vane (NGV) has been conducted in an annular sector to quantify aerodynamic influences of shower head (SH) and trailing edge (TE) cooling. The investigated vane is a typical high pressure gas turbine vane, geometrically similar to a real engine component, operated at a reference exit Mach number of 0.89. The investigations have been performed for various coolant-to-mainstream mass-flux ratios. New loss equations are derived and implemented regarding coolant aerodynamic losses. Results lead to a conclusion that both TE cooling and SH film cooling increase the aerodynamic loss compared to an uncooled case. In addition, the TE cooling has higher aerodynamic loss compared to the SH cooling. Secondary losses decrease with inserting SH film cooling compared to the uncooled case. The TE cooling appears to have less impact on the secondary loss compared to the SH cooling. Area-averaged exit flow angles around midspan increase for the TE cooling.
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| 285. |
- Saha, Ranjan, 1984-, et al.
(författare)
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Suction and Pressure Side Film Cooling Influence on Vane Aero Performance in a Transonic Annular Cascade
- 2013
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Ingår i: Proceedings of the ASME Turbo Expo. - 9780791855225
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Konferensbidrag (refereegranskat)abstract
- An experimental study on a film cooled nozzle guide vane has been conducted in a transonic annular sector to observe the influence of suction and pressure side film cooling on aerodynamic performance. The investigated vane is a typical high pressure gas turbine vane, geometrically similar to a real engine component, operated at an exit reference Mach number of 0.89. The aerodynamic results using a five hole miniature probe are quantified and compared with the baseline case which is uncooled. Results lead to a conclusion that the aerodynamic loss is influenced substantially with the change of the cooling flow rate regardless the positions of the cooling rows. The aerodynamic loss is very sensitive to the blowing ratio and a value of blowing ratio higher than one leads to a considerable higher loss penalty. The suction side film cooling has larger influence on the aerodynamic loss compared to the pressure side film cooling. Pitch-averaged exit flow angles around midspan remain unaffected at moderate blowing ratio. The secondary loss decreases (greater decrease in the tip region compared to the hub region) with inserting cooling air for all cases compared to the uncooled case.
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| 286. |
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| 287. |
- Salomon Popa, Marianne, 1976-, et al.
(författare)
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Distant Master Program in Sustainable Energy Engineering : Self-assessment of the intake autumn 2004
- 2007
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Since 1997 the Department of Energy Technology (EGI) has offered the Sustainable Energy Engineering (SEE) MSc Program to over 200 students from around 50 different countries. In June 2004, it was decided by the KTH President to offer the International Master Program on Sustainable Energy Engineering (SEE) as a distance program. Based on this, EGI offered a distance version of the Sustainable Energy Engineering Program (identified as DSEE) for the academic years (2004/2005 and 2005/2006) on a trial basis to a selected group of qualified students. This is a complete e-learning program that is held in conjunction with the regular SEE-program, offering an alternative for those students who could be accepted for the regular SEE-program but who can not afford to participate in the on-campus courses. All mandatory courses are offered on-line and lectures can be followed either synchronously or asynchronously via internet.This report contains the status of the first students that started the program in autumn 2004 and highlights the experience gained during the first year of the distance program as well as the challenges and opportunities associated with offereing a distance program in energy technology.
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| 288. |
- Salomón Popa, Marianne, 1976-, et al.
(författare)
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Energy Potential of Coconut and Palm Oil Residues
- 2009
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Ingår i: 5th Dubrovnik Conference on Sustainable Development of Energy, Water and Environment Systems. - Dubrovnik : Faculty of Mechanical Engineering and Naval Architecture, Zagreb. - 9789536313976
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Konferensbidrag (refereegranskat)abstract
- Agricultural residues continue to attract interest for energy recovery purposes as a renewable, CO2 neutral and increasingly cost competitive alternative to traditional fossil fuels. The possibility of trigeneration in already established industries such palm oil mills and coconut processing plants is very attractive especially when residues that otherwise represent a disposal problem can be utilized efficiently. The use of these residues in rural areas or in small islands could certainly represent an advantage as the use of expensive fossil fuels represents an additional burden to foster development. Different technical scenarios for the production of electricity, process heat and biodiesel are analyzed using these residues Environmental aspects are also included in this analysis. Studies were done considering certain scenarios to evaluate the feasibility of using these residues for energy purposes. Residues were considered to be combusted directly in boilers and steam turbines were used as prime movers to generate electricity. Biodiesel is produced by transesterification of palm oil/coconut oil. The required process heat for palm oil or coconut oil processing is supplied by the residues as well as the steam required for biodiesel production. The advantage is that biodiesel is a more flexible and easy-to-distribute fuel that can be used for power generation or for transportation. The results shown that palm oil mills/coconut processing industries can be independent of fossil fuels. Furthermore, they can contribute positively to the energy balance of the communities by helping reduce the dependence on fossil fuels and reducing at the same time greenhouse gas emissions.
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| 289. |
- Salomon Popa, Marianne, 1976-, et al.
(författare)
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Energy Potential of Coconut and Palm Oil Residues : Selected Case Studies from Latin America and Small Island Developing States
- 2024
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Ingår i: Renewable & sustainable energy reviews. - : Elsevier. - 1364-0321 .- 1879-0690.
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Agricultural residues continue to attract interest for energy recovery purposes as a renewable, CO2 neutral and increasingly cost competitive alternative to traditional fossil fuels. The possibility of trigeneration in already established industries such as palm oil mills and coconut processing plants is very attractive especially when residues that otherwise represent a disposal problem can be utilized efficiently. Different technological scenarios for the production of electricity, process heat and biodiesel are analyzed using coconut and palm oil residues. Environmental aspects are also included in the analysis. Studies were conducted considering various scenarios to evaluate the feasibility of using these residues for energy purposes. The residues were considered to be combusted directly in steam boilers while steam turbines were used to generate electricity. Biodiesel is produced by transesterification of palm oil/coconut oil. The required process heat for palm oil or coconut oil processing as well as the steam required for biodiesel production is supplied by the combustion of the residues. The results show that palm oil mills/coconut processing industries can be independent of fossil fuels. Furthermore, they can contribute positively to the energy balance of the communities by helping reduce the dependence on fossil fuels and reducing simultaneously greenhouse gas emissions.
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| 290. |
- Salomon Popa, Marianne, 1976-, et al.
(författare)
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Gas turbine simulations in the computerized educational program CompEduHPT : Educational aspects
- 2003
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Ingår i: American Society of Mechanical Engineers, International Gas Turbine Institute, Turbo Expo (Publication) IGTI. ; , s. 733-739
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Konferensbidrag (refereegranskat)abstract
- An overview of computerized educational program (CompEduHPT) which includes several simulations was presented. These simulations provide an alternative way to learn, based on discovery and experience. All the simulations were preceded with theory chapters, quizzes and preparatory tasks to enable fruitful exercises to be designed. Evaluations show that a computerized program including multiple ways of learning provides considerable support to the conventional student-teacher way of learning.
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