The influence of the processes of utilization of exhaust gases of reciprocating internal combustion engines on the gas dynamic and acoustic characteristics of noise silencers

The scientific basis for the design of noise suppressors for internal combustion engines with exhaust gas heat recovery, providing the release of gas flows with improved gas-dynamic and acoustic characteristics, is presented. The thermodynamic analysis of the processes of energy utilization of exhaust gases has been studied. Thermodynamic analysis showed that the utilization of exhaust gas heat leads to an increase in the coefficient of performance (COP) of the Otto cycle. An exergy analysis of heat exchange processes in the muffler was also carried out, and ways to increase its thermodynamic efficiency were determined. It has been established that a noise silencer with a heat exchanger-coil installed inside, from the position of the second law of thermodynamics, expressed by means of exergy analysis, is a more advanced thermodynamic system compared to a conventional silencer. A mathematical description of the recycling processes under conditions of external thermal exposure is given, while the nature of the influence of thermal exposure on changes in pressure, temperature and density is established. Based on the method of L.A. Vulis analytical equations for changes in pressure, temperature and density are obtained. Exhaust gas energy recovery processes contribute to a decrease in gas temperature, an increase in density, a decrease in flow velocity and a pressure drop, i.e. there is an effect (law of L.A. Vulis) of thermal stagnation of the gas flow, which causes a decrease in the noise level with less back pressure and an increase in engine efficiency.

1. Quiros D. C., Smith J., Thiruvengadam A., Huai T. Greenhouse gas emissions from heavyduty natural gas, hybrid, and conventional diesel on-road trucks during freight transport. Atmospheric Environment, 2017, vol. 168, pp. 36–45. https:// doi.org/10.1016/j.atmosenv.2017.08.066

2. Trubaev P. A., Zajtsev E. А., Besedin P.V. Exergic analysis of technological heat devices. International Journal of Pharmacy and Technology, 2016, vol. 8, no. 4, pp. 24968–24975.

3. Vulis L.A. Thermodynamics of Gas Flows. Moscow, Leningrad, Gosenergoizdat Publ., 1950. 304 p. (in Russian).

4. Inzel L.I. Fundamentals of Muffling Exhaust Noise of Internal Combustion Engines. Moscow, Publishing House and 1st Type. Mashgiza in Lgd, 1949. 196 p. (in Russian).

5. Shatrov M. G., Yakovenko A. L., Krichevskaya T. Yu. Noise of Automobile Internal Combustion Engines. Moscow, Moscow Automobile and Road Engineering State Technical University, 2014. 68 p. (in Russian).

6. Grudanov V. Ya., Belokhvostov G. I., Tkacheva L.T. Scientific and practical approaches to improving the designs of noise dampers of piston internal combustion engines based on the theory of numbers. Nauka i tekhnika = Science and Technique, 2021, vol. 20, no. 5, pp. 434–444 (in Russian). https://doi.org/10.21122/2227-1031-2021-20-5-434-444

7. Grudanov V. Ya., Belokhvostov G. I., Tkacheva L.T. Modeling and optimization of hydraulic and acoustic characteristics of piston engine noise mufflers based on number theory. Gornaya mekhanika i mashinostroenie = Mining Mechanical Engineering and Machine-Building, 2020, no. 4, pp. 28–42 (in Russian).

8. Grudanov V. Ya., Filidovich E. N., Belokhvostov G.I. Number theory in the development of the machine-building complex of the Republic of Belarus. Inzhener-mekhanik [Mechanical Engineer], 2020, vol. 86, no. 1, pp. 7–9 (in Russian).

9. Grudanov V. Ya., Tkacheva L.T. Modeling and optimization of hydraulic and acoustic characteristics of piston engine noise silencers. Vestnik Belorussko-Rossiiskogo universiteta = The Belarusian-Russian University Herald, 2017, vol. 57, no. 4, pp. 17–28 (in Russian).

10. Ivanov N.I. The Fight Against Noise and Vibrations on Track and Construction Machines. Moscow, Transport Publ., 1978. 272 p. (in Russian).

11. Lubyanchenko A.A. Improvement of Vibroacoustic Characteristics of Noise Mufflers for the Release of High-Power Internal Combustion Engines. St. Petersburg, 2017. 22 p. (in Russian).

12. Drobakha M.N. Reduction of External Noise of Transport Vehicles with Silencers (on the Example of the MTZ-82 Tractor). St. Petersburg, 2004. 148 p. (in Russian).

13. Razumovskii M.A. Noise Control on Tractors. Minsk, Nauka i tekhnika Publ., 1973. 208 p. (in Russian).

14. Bezruchko A.F. Improving the Characteristics of Noise Silencers of Agricultural Tractors. Minsk, 1989. 15 p. (in Russian).

15. Komkin A.I. Development of Modern Methods of Calculation and Design of Automobile Mufflers with the Required Characteristics. St. Petersburg, 2012. 48 p. (in Russian).

16. Bykov A.I. Investigation of Acoustic Characteristics of Helmholtz Resonators in Noise Reduction Systems. St. Petersburg, 2021. 22 p. (in Russian).

17. Belotserkovsky S. V., Tolskyi V.E. The automobile mufflers: the modern requirements, tendencies of development, methods of calculations and tests. Tekhnicheskaya akustika = Technical Acoustics, 2001, no. 1, pp. 30–37 (in Russian).

18. Grudanov V. Ya., Tupal’sky K. N., Rubanov A.N. Exhaust gas heat utilizer. Avtomobil’naya promyshlennost’ [Automotive Industry], 1986, no. 7, pp. 11–12 (in Russian).

19. Grudanov V. Ya., Zhestkov S.V. Analysis and evaluation of the mathematical model of the processes of waste gas energy utilization. Izvestiya vysshikh uchebnykh zavedenii. Energetika. [News of Higher Educational Institutions. Energy], 1990, no. 9, pp. 13–16 (in Russian).

20. Grudanov V. Ya., Shirokov E.I. Mathematical modeling of the processes of utilization of the energy of exhaust gases of the internal combustion engine. Dvigatelestroyeniye, 1990, no. 9, pp. 13–16 (in Russian).

21. Babenko V. A., Grudanov V. Ya. Computational and experimental study of hydrodynamics and heat transfer in cooled automobile noise silencers. Problemy teplo- i massoobmena v protsessakh i apparatakh pri ispol’zovanii vtorichnykh energoresursov i al’ternativnykh istochnikakh energii: Mezhdunarodnaya shkola-seminar, sentyabr’, 1990 [Problems of Heat and Mass Transfer in Processes and Apparatuses Using Secondary Energy Resources and Alternative Energy Sources: International School-Seminar, September, 1990]. Minsk, A.V. Luikov Heat and Mass Transfer Institute of the Academy of Sciences of the BSSR, 1990, pp. 66–76 (in Russian).

22. Grudanov V. Ya., Osipov V.M. Heat transfer and hydraulic resistance in the processes of heat utilization of exhaust gases of internal combustion engines. Izvestiya vysshikh uchebnykh zavedenii Energetika [News of Higher Educational Institutions. Energy], 1990, no. 3, pp. 81–84 (in Russian).

23. Grudanov V. Ya. Physico-chemical and heat exchange processes in catalytic converters with utilization of exhaust gas heat. Dvigatelestroyeniye, 1991, no. 1, pp. 47–49 (in Russian).