Research Article
BibTex RIS Cite
Year 2018, Special Issue 7: International Conference on Energy and Thermal Engineering Istanbul 2017 (ICTE 2017), 1780 - 1790, 20.12.2017
https://doi.org/10.18186/journal-of-thermal-engineering.372968

Abstract

References

  • [1] European Environment Agency [EEA]. (2013). Trends and projections in Europe 2013: Tracking progress towards Europe's climate and energy targets until 2020. Report No 10/2013.
  • [2] Köse, H., Ciniviz, M. (2013). An experimental investigation of effect on diesel engine performance and exhaust emissions of addition at dual fuel mode of hydrogen. Fuel Processing Technology, 114, 26–34.
  • [3] Liu, Y., Yang, J., Sun, J., Zhu, A., Zhou, Q. A (2011). Phenomenological model for prediction auto-ignition and soot formation of turbulent diffusion combustion in a high pressure common rail diesel engine. International Journal of Hydrogen Energy, 4, 894-912.
  • [4] Nieminen, J., D'Souza, N., Dincer, I. (2010). Comparative combustion characteristics of gasoline and hydrogen fuelled ICEs. International Journal of Hydrogen Energy, 35, 5114-5123.
  • [5] Lata, D.B., Misra, A., Medhekar, S. (2012). Effect of hydrogen and LPG addition on the efficiency and emissions of a dual fuel diesel engine. International Journal of Hydrogen Energy, 37, 6084-6096.
  • [6] Lata, D.B., Misra, A., Medhekar, S. (2011). Investigations on the combustion parameters of a dual fuel diesel engine with hydrogen and LPG as secondary fuels. International Journal of Hydrogen Energy, 36, 13808-13819.
  • [7] He, Y., Mab, F., Deng, J., Shao, Y., Jian, X. (2012). Reducing the idle speed of an SI CNG engine fueled by HCNG with high hydrogen ratio. Int J Hydrogen Energy, 37, 8698-8703.
  • [8] Mohammed, S.E., Baharom, M.B., Aziz, A.R.A., Firmansyah. (2011). The effects of fuel-injection timing at medium injection pressure on the engine characteristics and emissions of a CNG-DI engine fueled by a small amount of hydrogen in CNG. International Journal of Hydrogen Energy, 36, 11997-12006.
  • [9] Xin, Z., Jian, X., Shizhuo, Z., Xiaosen, H., Jianhua, L. (2013). The experimental study on cyclic variation in a spark ignited engine fueled with biogas and hydrogen blends. International Journal of Hydrogen Energy, 38, 11164-11168.
  • [10] Park, C., Park, S., Lee, Y., Kim, C., Lee, S., Moriyoshi, Y. (2011). Performance and emission characteristics of a SI engine fueled by low calorific biogas blended with hydrogen. International Journal of Hydrogen Energy, 36, 10080-88.
  • [11] Greenwood, J.B., Erickson, P.A., Hwang, J., Jordan, E.A. (2014). Experimental results of hydrogen enrichment of ethanol in an ultra-lean internal combustion engine International Journal of Hydrogen Energy, 39, 12980-90.
  • [12] Ji, C., Liu, X., Wang, S., Gao, B., Yang, J. (2014). A laminar burning velocity correlation for combustion simulation of hydrogen-enriched ethanol engines. Fuel, 133, 139–142.
  • [13] Biffiger, H., Soltic, P. (2015). Effects of split port/direct injection of methane and hydrogen in a spark ignition engine. International Journal of Hydrogen Energy, 40, 1994-2003.
  • [14] Shivaprasad, K.V., Raviteja, S., Chitragar, P., Kumar, G.N. (2014). Experimental investigation of the effect of hydrogen addition on combustion performance and emissions characteristics of a spark ignition high speed gasoline engine. Procedia Technology, 14, 141–148.
  • [15] Saravanan, N., Nagarajan, G. (2009). Experimental investigation on performance and emission characteristics of dual fuel DI diesel engine with hydrogen fuel. SAE Paper No. 2009-26-032.
  • [16] Miyamoto, T., Mikami, M., Kojima, N., Kabashima, H., Urata, Y. (2009). Effect of hydrogen fraction in intake mixture on combustion and exhaust emission characteristics of a diesel engine. SAE Paper No. 2009-24-0086.
  • [17] Bika, A.S., Franklin, L.M., Kittelson, D.B. (2008). Emissions effects of hydrogen as a supplemental fuel with diesel and biodiesel. SAE Paper No. 2008-01-0648.
  • [18] Gomes-Antunes, J.M., Mikalsen, R., Roskilly, (2008). A.P. An investigation f hydrogen fuelled HCCI engine performance and operation. International Journal of Hydrogen Energy, 33, 5823–5828.
  • [19] Szwaja, S., Grab-Rogalinski, K., (2009). Hydrogen combustion in a compression ignition diesel engine. International Journal of Hydrogen Energy, 34, 4413–4421.
  • [20] Sopena, C., Dieguez, P.M., Sainz, D., Urroz, J.C., Guelbenzu, E., Gandia, L.M., (2010). Conversion of a commercial spark ignition engine to run on hydrogen: Performance comparison using hydrogen and gasoline. International Journal of Hydrogen Energy, 35, 1420-1429.
  • [21] Ji, C., Wang, S. (2009). Effect of hydrogen addition on the idle performance of a spark ignited gasoline engine at stoichiometric condition. International Journal of Hydrogen Energy, 34, 3546-3556.
  • [22] Wang, S., Ji, C., Zhang, M., Zhang, B. (2010). Reducing the idle speed of a spark-ignited gasoline engine with hydrogen addition. International Journal of Hydrogen Energy, 35 10580-88.
  • [23] Andrea, T.D., Henshaw, P.F., Ting, S.K. (2004). The addition of hydrogen to a gasoline fuelled SI engine. International Journal of Hydrogen Energy, 29, 1541-52.
  • [24] Karagöz, Y., Yüksek, L., Sandalcı, T., Dalkılıc, A.S. (2015). An experimental investigation on the performance characteristics of a hydroxygen enriched gasoline engine with water injection. International Journal of Hydrogen Energy, 40, 692-702.
  • [25] Hu, E., Huang, Z., Liu, B., Zheng, J., Gu, X., Huang B. (2009). Experimental investigation on performance and emissions of a spark-ignition engine fuelled with natural gas-hydrogen blends combined with EGR. I International Journal of Hydrogen Energy, 34, 528-539.
  • [26] Hu, E., Huang, Z., Liu, B., Zheng, J., Gu, X. (2009). Experimental study on combustion characteristics of a spark-ignition engine fuelled with natural gas-hydrogen blends combining with EGR. International Journal of Hydrogen Energy, 34, 1035-1044.
  • [27] Huang, B., Hu, E., Huang, Z., Zheng, J., Liu, B., Jiang, D. (2009). Cycle-by-cycle variations in a spark ignition engine fueled with natural gas-hydrogen blends combined with EGR. International Journal of Hydrogen Energy, 34, 8405-8414.
  • [28] Köten, H., Yilmaz, M., Gül, M.Z. (2014). Compressed bio gas [CBG]-diesel dual fuel engine optimization study for ultra-low emission”, JAME.
  • [29] Heywood, J.B. (1988). Internal Combustion Engine Fundamentals. McGraw Hill Inc. New York, USA.
  • [30] Miyamoto, T., Hasegawa, H., Mikami, M., Kojima, N., Kabashima, H., Urata, Y. (2011). Effect of hydrogen addition to intake gas on combustion and exhaust emission characteristics of a diesel engine. International Journal of Hydrogen Energy, 36, 13138-13149.
  • [31] Bose, P.K., Maji, D. (2009). An experimental investigation on engine performance and emissions of a single cylinder diesel engine using hydrogen as inducted fuel and diesel as injected fuel with exhaust gas recirculation. International Journal of Hydrogen Energy, 34, 4847– 4854.
  • [32] Gomes-Antunes, J.M., Mikalsen, R., Roskilly, A.P. (2009). An experimental study of a direct injection compression ignition hydrogen engine. International Journal of Hydrogen Energy, 34, 6516–6522.
  • [33] Ikegami, M., Miwa, M., Shioji, M. A (1982). Study on hydrogen fuelled compression ignition engines. International Journal of Hydrogen Energy, 7, 341-353.
  • [34] Christodoulou, F., Megaritis, A. (2013). Experimental investigation of the effects of separate hydrogen and nitrogen addition on the emissions and combustion of a diesel engine. International Journal of Hydrogen Energy, 38, 10126-10140.
  • [35] Pan, H., Pournazeri, S., Princevac, M., Miller, J.W., Mahalingam, S., Khan, M.Y., Jayaram, V., Welch, W.A. (2014). Effect of hydrogen addition on criteria and greenhouse gas emissions for a marine diesel engine. International Journal of Hydrogen Energy, 39, 11336-11345.
  • [36] Wu, H.W., Wu, Z.Y. (2012). Investigation on combustion characteristics and emissions of diesel/hydrogen mixtures by using energy-share method in a diesel engine. Applied Thermal Engineering, 42, 154-162.
  • [37] Hosseini, S.M., Ahmadi, R. (2017). Performance and emissions characteristics in the combustion of co-fuel diesel-hydrogen in a heavy duty engine. Applied Energy, 205, 911-925.
  • [38] Talibi, M., Hellier, P., Ladommatos, N. (2017). The effect of varying EGR and intake air boost on hydrogen-diesel co-combustion in CI engines. International Journal of Hydrogen Energy, 42, 6369-6383.
  • [39] Köten, H., Yilmaz, M., Gül, M.Z. (2012). Effects of the injection parameters and compression ratio on the emissions of a heavy duty diesel engine. 147-163.
  • [40] Pulkrabek, W.W. (2004). Engineering Fundamentals of the Internal Combustion Engine, Prentice Hall.
  • [41] Wei, L., Geng, P. (2016). A review on natural gas/diesel dual fuel combustion, emissions and performance. Fuel Processing Technology 142, 264–278.
  • [42] Heywood, JB. (1988). Internal Combustion Engine Fundamentals; McGraw Hill Inc. New York, USA, 1988.
  • [43] Fenimore, CP. (1971). Formation of nitric oxide in premixed hydrocarbon flames, Symp Combust, 13(1):373–380.
  • [44] Stiesch, DIG. (2003). Modeling Engine Spray and Combustion Processes. Springer Berlin Heidelberg.

EFFECT OF HYDROGEN ADDITION AT DIFFERENT LEVELS ON EMISSIONS AND PERFORMANCE OF A DIESEL ENGINE

Year 2018, Special Issue 7: International Conference on Energy and Thermal Engineering Istanbul 2017 (ICTE 2017), 1780 - 1790, 20.12.2017
https://doi.org/10.18186/journal-of-thermal-engineering.372968

Abstract

The ratio of diesel vehicles in vehicle park and also the number of
diesel vehicles sharply increase in the world. Advantages of diesel engines can
be stated as high efficiency, low fuel consumption etc., on the other hand high
amount of oxides of nitrogen caused by high compression ratio of diesel engines
should be noted as its disadvantage.    Moreover, a high amount of smoke emission is
formed due to combustion characteristics of diesel engines. Both NOx and smoke
are really hazardous for the environment. Stringent emission regulations force
diesel engines to exhaust less NOx and smoke emissions. Thus, diesel
engines require advanced after - treatment systems. The catalyst materials in
after - treatment systems are really expensive. In this study, different levels
of hydrogen [0%, 40% and 75%] on energy basis of total fuel were introduced
into intake manifold of engine. Brake thermal efficiency of the engine improved
with increasing percentage of hydrogen. CO, THC and smoke emissions are
significantly decreased by using hydrogen as additional fuel. Especially, a
novel decrease on smoke emission [up to 70.7%] is obtained. However,
particularly during 75% hydrogen addition, the dramatic increase in NOx
emissions could not be prevented.

References

  • [1] European Environment Agency [EEA]. (2013). Trends and projections in Europe 2013: Tracking progress towards Europe's climate and energy targets until 2020. Report No 10/2013.
  • [2] Köse, H., Ciniviz, M. (2013). An experimental investigation of effect on diesel engine performance and exhaust emissions of addition at dual fuel mode of hydrogen. Fuel Processing Technology, 114, 26–34.
  • [3] Liu, Y., Yang, J., Sun, J., Zhu, A., Zhou, Q. A (2011). Phenomenological model for prediction auto-ignition and soot formation of turbulent diffusion combustion in a high pressure common rail diesel engine. International Journal of Hydrogen Energy, 4, 894-912.
  • [4] Nieminen, J., D'Souza, N., Dincer, I. (2010). Comparative combustion characteristics of gasoline and hydrogen fuelled ICEs. International Journal of Hydrogen Energy, 35, 5114-5123.
  • [5] Lata, D.B., Misra, A., Medhekar, S. (2012). Effect of hydrogen and LPG addition on the efficiency and emissions of a dual fuel diesel engine. International Journal of Hydrogen Energy, 37, 6084-6096.
  • [6] Lata, D.B., Misra, A., Medhekar, S. (2011). Investigations on the combustion parameters of a dual fuel diesel engine with hydrogen and LPG as secondary fuels. International Journal of Hydrogen Energy, 36, 13808-13819.
  • [7] He, Y., Mab, F., Deng, J., Shao, Y., Jian, X. (2012). Reducing the idle speed of an SI CNG engine fueled by HCNG with high hydrogen ratio. Int J Hydrogen Energy, 37, 8698-8703.
  • [8] Mohammed, S.E., Baharom, M.B., Aziz, A.R.A., Firmansyah. (2011). The effects of fuel-injection timing at medium injection pressure on the engine characteristics and emissions of a CNG-DI engine fueled by a small amount of hydrogen in CNG. International Journal of Hydrogen Energy, 36, 11997-12006.
  • [9] Xin, Z., Jian, X., Shizhuo, Z., Xiaosen, H., Jianhua, L. (2013). The experimental study on cyclic variation in a spark ignited engine fueled with biogas and hydrogen blends. International Journal of Hydrogen Energy, 38, 11164-11168.
  • [10] Park, C., Park, S., Lee, Y., Kim, C., Lee, S., Moriyoshi, Y. (2011). Performance and emission characteristics of a SI engine fueled by low calorific biogas blended with hydrogen. International Journal of Hydrogen Energy, 36, 10080-88.
  • [11] Greenwood, J.B., Erickson, P.A., Hwang, J., Jordan, E.A. (2014). Experimental results of hydrogen enrichment of ethanol in an ultra-lean internal combustion engine International Journal of Hydrogen Energy, 39, 12980-90.
  • [12] Ji, C., Liu, X., Wang, S., Gao, B., Yang, J. (2014). A laminar burning velocity correlation for combustion simulation of hydrogen-enriched ethanol engines. Fuel, 133, 139–142.
  • [13] Biffiger, H., Soltic, P. (2015). Effects of split port/direct injection of methane and hydrogen in a spark ignition engine. International Journal of Hydrogen Energy, 40, 1994-2003.
  • [14] Shivaprasad, K.V., Raviteja, S., Chitragar, P., Kumar, G.N. (2014). Experimental investigation of the effect of hydrogen addition on combustion performance and emissions characteristics of a spark ignition high speed gasoline engine. Procedia Technology, 14, 141–148.
  • [15] Saravanan, N., Nagarajan, G. (2009). Experimental investigation on performance and emission characteristics of dual fuel DI diesel engine with hydrogen fuel. SAE Paper No. 2009-26-032.
  • [16] Miyamoto, T., Mikami, M., Kojima, N., Kabashima, H., Urata, Y. (2009). Effect of hydrogen fraction in intake mixture on combustion and exhaust emission characteristics of a diesel engine. SAE Paper No. 2009-24-0086.
  • [17] Bika, A.S., Franklin, L.M., Kittelson, D.B. (2008). Emissions effects of hydrogen as a supplemental fuel with diesel and biodiesel. SAE Paper No. 2008-01-0648.
  • [18] Gomes-Antunes, J.M., Mikalsen, R., Roskilly, (2008). A.P. An investigation f hydrogen fuelled HCCI engine performance and operation. International Journal of Hydrogen Energy, 33, 5823–5828.
  • [19] Szwaja, S., Grab-Rogalinski, K., (2009). Hydrogen combustion in a compression ignition diesel engine. International Journal of Hydrogen Energy, 34, 4413–4421.
  • [20] Sopena, C., Dieguez, P.M., Sainz, D., Urroz, J.C., Guelbenzu, E., Gandia, L.M., (2010). Conversion of a commercial spark ignition engine to run on hydrogen: Performance comparison using hydrogen and gasoline. International Journal of Hydrogen Energy, 35, 1420-1429.
  • [21] Ji, C., Wang, S. (2009). Effect of hydrogen addition on the idle performance of a spark ignited gasoline engine at stoichiometric condition. International Journal of Hydrogen Energy, 34, 3546-3556.
  • [22] Wang, S., Ji, C., Zhang, M., Zhang, B. (2010). Reducing the idle speed of a spark-ignited gasoline engine with hydrogen addition. International Journal of Hydrogen Energy, 35 10580-88.
  • [23] Andrea, T.D., Henshaw, P.F., Ting, S.K. (2004). The addition of hydrogen to a gasoline fuelled SI engine. International Journal of Hydrogen Energy, 29, 1541-52.
  • [24] Karagöz, Y., Yüksek, L., Sandalcı, T., Dalkılıc, A.S. (2015). An experimental investigation on the performance characteristics of a hydroxygen enriched gasoline engine with water injection. International Journal of Hydrogen Energy, 40, 692-702.
  • [25] Hu, E., Huang, Z., Liu, B., Zheng, J., Gu, X., Huang B. (2009). Experimental investigation on performance and emissions of a spark-ignition engine fuelled with natural gas-hydrogen blends combined with EGR. I International Journal of Hydrogen Energy, 34, 528-539.
  • [26] Hu, E., Huang, Z., Liu, B., Zheng, J., Gu, X. (2009). Experimental study on combustion characteristics of a spark-ignition engine fuelled with natural gas-hydrogen blends combining with EGR. International Journal of Hydrogen Energy, 34, 1035-1044.
  • [27] Huang, B., Hu, E., Huang, Z., Zheng, J., Liu, B., Jiang, D. (2009). Cycle-by-cycle variations in a spark ignition engine fueled with natural gas-hydrogen blends combined with EGR. International Journal of Hydrogen Energy, 34, 8405-8414.
  • [28] Köten, H., Yilmaz, M., Gül, M.Z. (2014). Compressed bio gas [CBG]-diesel dual fuel engine optimization study for ultra-low emission”, JAME.
  • [29] Heywood, J.B. (1988). Internal Combustion Engine Fundamentals. McGraw Hill Inc. New York, USA.
  • [30] Miyamoto, T., Hasegawa, H., Mikami, M., Kojima, N., Kabashima, H., Urata, Y. (2011). Effect of hydrogen addition to intake gas on combustion and exhaust emission characteristics of a diesel engine. International Journal of Hydrogen Energy, 36, 13138-13149.
  • [31] Bose, P.K., Maji, D. (2009). An experimental investigation on engine performance and emissions of a single cylinder diesel engine using hydrogen as inducted fuel and diesel as injected fuel with exhaust gas recirculation. International Journal of Hydrogen Energy, 34, 4847– 4854.
  • [32] Gomes-Antunes, J.M., Mikalsen, R., Roskilly, A.P. (2009). An experimental study of a direct injection compression ignition hydrogen engine. International Journal of Hydrogen Energy, 34, 6516–6522.
  • [33] Ikegami, M., Miwa, M., Shioji, M. A (1982). Study on hydrogen fuelled compression ignition engines. International Journal of Hydrogen Energy, 7, 341-353.
  • [34] Christodoulou, F., Megaritis, A. (2013). Experimental investigation of the effects of separate hydrogen and nitrogen addition on the emissions and combustion of a diesel engine. International Journal of Hydrogen Energy, 38, 10126-10140.
  • [35] Pan, H., Pournazeri, S., Princevac, M., Miller, J.W., Mahalingam, S., Khan, M.Y., Jayaram, V., Welch, W.A. (2014). Effect of hydrogen addition on criteria and greenhouse gas emissions for a marine diesel engine. International Journal of Hydrogen Energy, 39, 11336-11345.
  • [36] Wu, H.W., Wu, Z.Y. (2012). Investigation on combustion characteristics and emissions of diesel/hydrogen mixtures by using energy-share method in a diesel engine. Applied Thermal Engineering, 42, 154-162.
  • [37] Hosseini, S.M., Ahmadi, R. (2017). Performance and emissions characteristics in the combustion of co-fuel diesel-hydrogen in a heavy duty engine. Applied Energy, 205, 911-925.
  • [38] Talibi, M., Hellier, P., Ladommatos, N. (2017). The effect of varying EGR and intake air boost on hydrogen-diesel co-combustion in CI engines. International Journal of Hydrogen Energy, 42, 6369-6383.
  • [39] Köten, H., Yilmaz, M., Gül, M.Z. (2012). Effects of the injection parameters and compression ratio on the emissions of a heavy duty diesel engine. 147-163.
  • [40] Pulkrabek, W.W. (2004). Engineering Fundamentals of the Internal Combustion Engine, Prentice Hall.
  • [41] Wei, L., Geng, P. (2016). A review on natural gas/diesel dual fuel combustion, emissions and performance. Fuel Processing Technology 142, 264–278.
  • [42] Heywood, JB. (1988). Internal Combustion Engine Fundamentals; McGraw Hill Inc. New York, USA, 1988.
  • [43] Fenimore, CP. (1971). Formation of nitric oxide in premixed hydrocarbon flames, Symp Combust, 13(1):373–380.
  • [44] Stiesch, DIG. (2003). Modeling Engine Spray and Combustion Processes. Springer Berlin Heidelberg.
There are 44 citations in total.

Details

Journal Section Articles
Authors

Yasin Karagöz

Publication Date December 20, 2017
Submission Date July 28, 2017
Published in Issue Year 2018 Special Issue 7: International Conference on Energy and Thermal Engineering Istanbul 2017 (ICTE 2017)

Cite

APA Karagöz, Y. (2017). EFFECT OF HYDROGEN ADDITION AT DIFFERENT LEVELS ON EMISSIONS AND PERFORMANCE OF A DIESEL ENGINE. Journal of Thermal Engineering, 4(2), 1780-1790. https://doi.org/10.18186/journal-of-thermal-engineering.372968
AMA Karagöz Y. EFFECT OF HYDROGEN ADDITION AT DIFFERENT LEVELS ON EMISSIONS AND PERFORMANCE OF A DIESEL ENGINE. Journal of Thermal Engineering. December 2017;4(2):1780-1790. doi:10.18186/journal-of-thermal-engineering.372968
Chicago Karagöz, Yasin. “EFFECT OF HYDROGEN ADDITION AT DIFFERENT LEVELS ON EMISSIONS AND PERFORMANCE OF A DIESEL ENGINE”. Journal of Thermal Engineering 4, no. 2 (December 2017): 1780-90. https://doi.org/10.18186/journal-of-thermal-engineering.372968.
EndNote Karagöz Y (December 1, 2017) EFFECT OF HYDROGEN ADDITION AT DIFFERENT LEVELS ON EMISSIONS AND PERFORMANCE OF A DIESEL ENGINE. Journal of Thermal Engineering 4 2 1780–1790.
IEEE Y. Karagöz, “EFFECT OF HYDROGEN ADDITION AT DIFFERENT LEVELS ON EMISSIONS AND PERFORMANCE OF A DIESEL ENGINE”, Journal of Thermal Engineering, vol. 4, no. 2, pp. 1780–1790, 2017, doi: 10.18186/journal-of-thermal-engineering.372968.
ISNAD Karagöz, Yasin. “EFFECT OF HYDROGEN ADDITION AT DIFFERENT LEVELS ON EMISSIONS AND PERFORMANCE OF A DIESEL ENGINE”. Journal of Thermal Engineering 4/2 (December 2017), 1780-1790. https://doi.org/10.18186/journal-of-thermal-engineering.372968.
JAMA Karagöz Y. EFFECT OF HYDROGEN ADDITION AT DIFFERENT LEVELS ON EMISSIONS AND PERFORMANCE OF A DIESEL ENGINE. Journal of Thermal Engineering. 2017;4:1780–1790.
MLA Karagöz, Yasin. “EFFECT OF HYDROGEN ADDITION AT DIFFERENT LEVELS ON EMISSIONS AND PERFORMANCE OF A DIESEL ENGINE”. Journal of Thermal Engineering, vol. 4, no. 2, 2017, pp. 1780-9, doi:10.18186/journal-of-thermal-engineering.372968.
Vancouver Karagöz Y. EFFECT OF HYDROGEN ADDITION AT DIFFERENT LEVELS ON EMISSIONS AND PERFORMANCE OF A DIESEL ENGINE. Journal of Thermal Engineering. 2017;4(2):1780-9.

IMPORTANT NOTE: JOURNAL SUBMISSION LINK http://eds.yildiz.edu.tr/journal-of-thermal-engineering