Liquid-Cooling System of an Aircraft Compression Ignition Engine: A CFD Analysis

Abstract

The present work deals with an analysis of the cooling system for a two-stroke aircraft engine with compression ignition. This analysis is carried out by means of a 3D finite-volume RANS equations solver with k- ϵ closure. Three different cooling system geometries are critically compared with a discussion on the capabilities and limitations of each technical solution. A first configuration of such a system is considered and analyzed by evaluating the pressure loss across the system as a function of the inlet mass-flow rate. Moreover, the velocity and vorticity patterns are analyzed to highlight the features of the flow structure. Thermal effects on the engine structure are also taken into account and the cooling system performance is assessed as a function of both the inlet mass-flow rate and the cylinder jackets temperatures. Then, by considering the main thermo-fluid dynamics features obtained in the case of the first configuration, two geometrical modifications are proposed to improve the efficiency of the system. As regards the first modification, the fluid intake is split in two manifolds by keeping the same total mass-flow rate. As regards the second configuration, a new single-inlet geometry is designed by inserting restrictions and enlargements within the cooling system to constrain the coolant flow through the cylinder jackets and by moving downstream the outflow section. It is shown that the second geometry modification achieves the best performances by improving the overall transferred heat of about 20% with respect to the first one, while keeping the three cylinders only slightly unevenly cooled. However, an increase of the flow characteristic loads occurs due to the geometrical restrictions and enlargements of the cooling system.

CFD modelling on flow field characteristics of engine cooling water jacket and its cooling performance improvement based on coolant transport path analysis method

“…Through a general review about CFD application in flow field characteristics analysis of engine cooling water jacket, it shows that CFD technology has obvious advantages in predicting evaluation parameters for fluid flow characteristics (coolant flow velocity and flowrate distributions, HTC distribution). [32][33][34][35][36] Through the CFD results theoretically guide the design and optimization process, the improvement for achieving a well-cooled engine products can be obtained easily.…”

CFD Analysis and Optimization of a Diesel Engine Cooling Water Jacket

“…The liquid cooling systems have the advantage of being able to keep the temperature of all of the cylinders quite even. In addition, the coolant is usually thermostatically controlled, so that the engine heats up quickly when starting, and always works all the time around the optimal operating temperature [6]. The diesel engine model in this paper also chooses the liquid cooling system.…”

A Comprehensive Numerical Analysis of the Scavenging Process in a Uniflow Two-Stroke Diesel Engine for General Aviation

“…This work aims to numerically analyze the scavenging of a two-stroke, multi-cylinder diesel engine by using a 3D CFD approach. The engine, referred to as GF56 [20], consists of six cylinders in a boxer water-cooled configuration [21], with a total displacement of 5600 cc, and is designed for the general aviation market, specifically for light aircraft applications. The engine has a uniflow scavenging configuration, consisting of eighteen intake ports around the cylinder liner and two exhaust valves on the cylinder head.…”