Experimental and numerical study of an internal combustion engine coolant flow distribution

Ujednačeno hlađenje svih cilindara u motoru s unutarnjim izgaranjem predstavlja trajni izazov za mnoge inženjere i istraživače. Različiti tok i brzina strujanja rashladnog sredstva na sličnim mjestima u cilindrima može rezultirati prevelikim ili preslabim hlađenjem nekih mjesta. U ovom se radu želi dobiti motor s ujednačenijim hlađenjem. U tu su svrhu najprije riješene jednadžbe protoka 1D i 3D kako bi se dobili numerički podaci o brzini, tlaku i temperaturi na različitim mjestima postojećeg motora. Tada se primijenila metoda mjerenja brzine fotogramom čestica (Particle Image Velocimetry - PIV) kako bi se na providnom poklopcu glave cilindra izrađenom od pleksiglasa provjeravale numeričke simulacije. Nakon provjere, u svrhu postizanja odgovarajućeg hlađenja, primijenile su se neke strategije kao na primjer male modifikacije na ulazu i izlazu rashladnog sredstva u motor kao i brzine protoka sredstva, a to je rezultiralo ujednačenijim hlađenjem, dakle onemogućavanjem prevelikog ili premalog hlađenja.Uniform cooling of all cylinders in an Internal Combustion Engine has been a continual challenge of many engineers and researchers. Different flow rate and velocity of coolant at similar locations of cylinders may cause some regions to be overcooled whereas some to be undercooled. In this study more uniform cooling engine is desired. To do this, at first the governing equations of the flow were solved 1D and 3D to obtain the velocity, pressure and temperature at various points of an existing engine numerically. Then Particle Image Velocimetry (PIV) method on a transparent cylinder head made of Plexiglas was used to validate the numerical simulations. After validation, in order to reach intelligent cooling, some strategies such as small modifications in the engine coolant inlet and outlet along with its flow rates were applied that resulted in more uniform cooling which in turn prevents any over and under cooling

A smart load-speed sensitive cooling map to have a high- performance thermal management system in an internal combustion engine

Considering the fact that electrification is increasingly used in internal combustion engines, this paper aims at presenting a smart speed-load sensitive cooling map for better thermal management. For this purpose, first, thermal boundary conditions for the engine cooling passage were obtained by thermodynamic and combustion simulation. Next, the temperature distribution of the cooling passage walls was determined using conjugate heat transfer method. Then, the effect of engine load on wall temperature distribution was investigated, and it was observed that in the conventional mode where the cooling flow is only affected by the engine speed, the engine is faced with over-cooling and under-cooling. Therefore, the optimum flow for cooling the engine was achieved in such a way that the engine is hot enough and kept free from damage, while the engine has a more uniform temperature distribution. These calculations were performed by considering the boiling phenomenon. The results showed using the cooling map leads to a significant reduction in coolant flow, which in turn reduces the power consumption of the water pump and size of the radiator. Moreover, fuel consumption, hydrocarbon emission production, and the needed power of the coolant pump are enhanced by 2.1, 8.6, and 44.3%, respectively.Irankhodro Powertrain Company (IPCo)http://www.elsevier.com/locate/energy2022-04-22hj2021Mechanical and Aeronautical Engineerin