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UAS Propulsion System Design
Published in R. Kurt Barnhart, Douglas M. Marshall, Eric J. Shappee, Introduction to Unmanned Aircraft Systems, 2021
Michael T. Most, Graham Feasey
A coolant system removes heat from the engine to prevent damage to the engine due to the immense heat generated; however, not all engines require a coolant system. Gas turbine engines are cooled by the high volume of air they ingest. Small reciprocating engines transfer sufficient heat directly to the air with the aid of cooling fins on the engine cylinder. Larger reciprocating and rotary engines require a coolant system to help remove some of the heat. Coolant is forced through channels in the combustion chamber and out to an air-cooled radiator. The coolant is usually a mixture of water and either ethylene glycol or propylene glycol and additives. This mixture depresses the freezing point (antifreeze) and raises the boiling point when compared with pure water. Through the block, the coolant must have sufficient flow and pressure to prevent nucleate boiling that causes erosion of the engine block. The radiator cap maintains an elevated system pressure by incorporating a spring-loaded seal. A coolant tank ensures that the system remains filled and provides expansion space for the hot coolant. As with the oil system, the coolant pump is either electrically driven or mechanically powered off the engine. A temperature control valve proportions the flow of coolant to the radiator to maintain the required temperature into the engine.
Lubrication and cooling
Published in Andrew Livesey, Motorcycle Engineering, 2021
The liquid used in a cooling system is usually called coolant, because it cools the engine. The coolant is a mixture of water, antifreeze, and a chemical that inhibits corrosion to the metal parts inside the engine. As you probably know, water boils at 100 °C (212 °F) and freezes at 0 °C (32 °F). This means that in winter water could freeze and damage the engine. Typically the coolant mixture boils at about 110 °C (230 °F) and freezes at about –18 °C (0 °F).
Lubrication and cooling
Published in Andrew Livesey, Practical Motorsport Engineering, 2019
The liquid used in a cooling system is usually called the coolant, because it cools the engine. The coolant is a mixture of water, anti-freeze and a chemical that inhibits corrosion to the metal parts inside the engine. As you probably know, water boils at 100 oC (212 oF) and freezes at 0 oC (32 oF). This means that in winter water could freeze and damage the engine. Typically the coolant mixture boils at about 110 oC (230 oF) and freezes at about –18 oC (0 oF).
Enhancement of grinding performances using fabricated pore aligned grinding wheels with PCA-GRA
Published in Materials and Manufacturing Processes, 2023
Hepsi Beaula M J, K. Jayakumar
In a dry grinder, surface damage cannot be prevented. Researchers have addressed this issue by several methods like Semi-Dry machining (SDM), Minimum Quantity Lubricant (MQL), etc.[5,6] Many researchers have recently used MQL in many machining areas to minimize tool wear and increase machined surface quality.[7] Grinding with abrasives is an essential method of machining heavy materials. At higher temperatures during grinding, the burning behavior of the device occurs. In such cases, micro-cracks are formed on the surface area, which is a significant threat to poor surface finish. To avoid the problems listed above, low cycle speeds or short material removal speeds are always recommended; however, this can lead to unnecessary productivity delays, thermal damage, and a poor finish. Coolant is often used in the machine to improve the life of the device and improve surface integrity.[8] The cooling function during the grinding operation is determined by the cooling temperature in the grinding zone.[9]