The application of a wave action design technique with minimal cost on a turbocharged engine equipped with water cooled charge air cooler aimed for energy management
Résumé
The vast majority of today's cars remain powered by gasoline or Diesel engines. In the European market, Diesel cars accounts for 55% of all new registrations While gasoline cars for 44%. All the other technologies such as hybrids, fully electric or natural gas and ethanol powered cars combine to make up the remaining 1%. Despite the publicity on these highly anticipated alternative technologies, statistics indicate that their usage remains marginal when compared to more 'traditional' powertrains. The internal combustion engine remains the principal way of transportation, at least for the foreseeable years. That being said, undesirable emissions (HC, CO, NOx, PM) are today's major concern because of their negative impact on air quality and global warming. The latest Euro 6 standard limits the CO emissions on a gasoline engine to 68% and the PM (particulate matter) on a Diesel engine to 96% lower than those established in 1992. CO2 emissions which are directly proportional to consumption rates are recently added to the list with a target of 95g/Km for 2020.
The main trend for solving these issues is through engine downsizing with high rates of turbocharging accompanied by fuel injection control, after-treatment and system integration. Techniques that increment the energy saving costs. The iccr (International Council on Clean Transportation) estimates that the cost of taking a 4-cylinder 1.5L Diesel engine from no emission controls to the Euro 6 standard is around -US81400. A major technique to gain control of the engine processes and achieve high performance and low emission levels is through air handling depicted by air intake tuning, turbocharging tuning and charge air cooling.
This article briefly describes the air intake line of 4-cylinder 1.5L turbocharged Diesel engine and investigates the role of wave action phenomena on its intake line. The goal here is to achieve lower consumption and better performance by finding the optimal intake geometry. The latter comprises of a compressor wheel, a water cooled charge air cooler prototype (WCAC) and connecting pipes. The wave action effects were first explained and highlighted on a dynamic flow bench at "Mann+Hummer using a frequency modeling approach which enabled to find the optimal length of piping upstream and downstream of the WCAC. Next this length was experimentally verified by mounting the different length on an engine test bench and registering pressure wave amplitudes. Finally the pressure recordings were fed to engine simulation software GT-Power (TM) for a transient low speed simulation mimicking urban driving conditions and specific fuel consumption data were recovered.
The result is a proposed air intake line for a turbocharged engine with a water cooled charge air cooler design choice. The proposed changes do not add any engine costs, but invests in significant R&D and retooling.