© Volodymyr Fedorov, Ph.D., Associate Professor,
ORCID:0000-0002-1085-5112;
е-mail: fedorov.volodymyr@gmail.com;
© Galyna Filipova, Ph.D., Professor;
ORCID:0000-0003-3427-7633;
е-mail: galina_gaj@ukr.net;
© Volodymyr Bosenko, Ph.D., Associate Professor;
ORCID:0000-0002-9654-949X;
е-mail: bosia4ok@ukr.net
(National Transport University)
“BLACK HOLE” NOISE MUFFLER AS A MEANS OF IMPROVING THE CAMOU-FLAGE PROPERTIES OF THE KRAZ-5233VE “SPETSNAZ” MILITARY VEHICLE
DOI:10.33868/0365-8392-2025-3-284-52-56
Abstract. For military equipment, in addition to the main operational characteristics (traction and speed, braking, fuel efficiency, controllability, stability, smoothness of movement and passability), camouflage characteristics are also extremely important. It refers to the ability of military equipment to covertly disguise in order to prevent or eliminate signs of exposure of troops and objects. Concealment is ensured by the use of camouflage, masking under the background with improvised means, creating smoke screens, using camouflage coatings, sound masking, etc. There are two funda-mentally opposite types of sound masking: either the creation of noise barriers, in which it is necessary to hide the noise of military equipment, or the creation of “silent” military equipment by reducing the level of external noise. For the KrAZ-5233VE “Spetsnaz” vehicle, which belongs to military equipment, a vital characteristic is the level of camouflage properties. It is obvious that reducing its level of external noise helps to improve the masking properties of the latter. The main sources of external car noise are the engine, body and wheels. In the noise of the internal combustion engine (ICE), the most powerful component is the noise of exhaust gases. That is, in order to reduce the external noise level of the car, it is necessary either to improve the existing muffler of the exhaust gases of the internal combustion engine, or to create a new acoustically highly effective muffler. Given that the development of exhaust silencers has been going on for over a century, the need for new approaches to solving this problem is almost obvious. When developing the muffler, the model of a completely black body popular in optics was taken as a basis in the form of an isolated macrocavity with a small hole: the beam, having entered the cavity through the hole, undergoes multiple reflections, is partially absorbed during each of them and practically does not return from there. A mathematical model of the operation of this muffler has been developed (the results of muffler efficiency calculations are provided). A forecast of the dependence of the exter-nal noise level of the KrAZ-5233VE “Spetsnaz” vehicle on the speed of movement was made.
Keywords: car, KrAZ-5233VE “Spetsnaz”, noise, camouflage, silencer, exhaust gases, completely black body, black hole, engine, trunk cycle.
References
1. KRAZ. (2024). KRAZ-5233VE. Retrieved from https://banga.ua/pages/avtomobili-kraz/bortovoy-kraz-5233be.
2. V. V. Fedorov, V. P. Sakhno. (2005). Utility model patent No. 79130 UA, IPC (2006) F01N 1/06. Exhaust silencer. National Transport University. Application 09.02.2005; Publ. 05/25/2007; Bul. No. 7.