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Exhaust temperature models are widely used in the automotive industry to estimate catalyst and exhaust gas temperatures and to protect the catalyst and other vehicle hardware against over-temperature conditions. Modeled exhaust temperatures rely on air, fuel, and spark measurements to make their estimate. Errors in any of these measurements can have a large impact on the accuracy of the model. Furthermore, air-fuel imbalances, air leaks, engine coolant temperature (ECT) or air charge temperature (ACT) inaccuracies, or any unforeseen source of heat entering the exhaust may have a large impact on the accuracy of the modeled estimate. Modern universal exhaust gas oxygen (UEGO) sensors have heaters with controllers to precisely regulate the oxygen sensing element temperature. These controllers are duty cycle based and supply more or less current to the heating element depending on the temperature of the surrounding exhaust gas.

The use of nanotechnology to develop advanced heat-transfer materials is a rapidly growing topic of research at facilities around the world. One class of these materials, nanofluids, has shown promise in the laboratory to dramatically improve thermal conductivity. Quantification of the thermophysical properties of these fluids is important for optimizing the design of automotive powertrains and electrical subsystems in order to produce highly efficient and robust vehicle cooling. A new technique for measuring thermal conductivity, the Transient Planar Source (TPS) method, was used for the first time to investigate the thermal conductivity of automotive coolants and their equivalent nanofluid, as a function of temperature. The results of this study indicate that the TPS method allows for rapid and repeatable measurement of thermal conductivity with an error of between 2-4%. The technique also presents several advantages over other methods which we will briefly describe.

A vehicle fleet test has been conducted to determine if octane advantages due to selected cooling system variables persist with stabilized deposits. The variables tested were reduced coolant temperatures, a direct substitution of aluminum for the iron cylinder head and an aluminum head with Unique Cooling. Octane requirements, octane requirement increase (ORI), emissions and fuel economy results are presented and discussed. Engine tests to determine the sensitivity of octane to independently controlled engine temperatures confirmed the primary dependence upon coolant temperature. Additional tests identified some of the variables which cause octane differences among the cylinders of one engine and between engine families.

In automotive assembly facilities worldwide, many critical vehicle systems such as brakes, power steering, radiator, and air conditioning require the appropriate fluid to function. In order to insure that these critical vehicle systems receive the correct amount of properly treated fluid, automotive manufacturers employ a method called Evacuation and Fill. Due to their closed-loop design, many critical vehicle systems must be first exposed to vacuum prior to being flooded with fluid. Only after the evacuation and fill process is complete will the critical vehicle system be able to perform as specified. It has long been thought, but never proven, that humidity and entrenched fluid were major hindrances to the Evacuation and Fill process. Consequently, Ford Motor Company Advanced Manufacturing Technology Development, Sandalwood Enterprises, Kettering University, and Dominion Tool & Die conducted a detailed project on this subject.

This paper describes (1) the development of a component test methodology for testing a cooling module including radiator, condenser and trans. cooler, and (2) the associated CAE model development. A series of light truck/SUV cooling module component tests were conducted to obtain their characteristics as inputs for frontal impact and sensor modeling development. First, the cooling module component CAE sub-model was developed using soft springs along with fine-mesh sheet metal shell elements. Second, simulated sub-model results were correlated fairly well with the test data. Third, this component CAE sub-model was then incorporated into a full vehicle CAE model that was used for frontal impact (NCAP) and sensor development. Results indicated that the proposed test method for cooling module components provided consistent data and the results from cooling module sub-model can be incorporated into the full vehicle CAE model for improving the quality and accuracy of CAE models.

The lack of electrical conductivity on materials, which are used in automotive fuel systems, can lead to electrostatic charges buildup in the components of such systems. This accumulation of energy can reach levels that exceed their capacity to withstand voltage surges, which considerably increases the risk of electrical discharges or sparks. Another important factor to consider is the conductivity of the commercially available fuels, such as biodiesel, which contributes to dissipate these charges to a proper grounding point in automobiles. From 2013, the diesel regulation in Brazil have changed and the levels of sulfur in the composition of diesel were reduced considerably, changing its natural characteristic of promoting electrostatic discharges, becoming more insulating.

In this paper, the high-temperature capability of the traction inverter was investigated by applying coolant with temperature much higher than the typical allowed value until the system fails. The purpose of this study is to identify the weakest link of the traction inverter system in terms of temperature. This study was divided into two stages. In the first stage, a series of nondestructive tests were carried out to investigate temperature rise (ΔT) of the key component above coolant temperature as a function of the outside controllable parameters-i.e., dc link voltage, phase current, and switching frequency. The key components include power modules, gate driver board, gate driver power supply, current sensors and dc link capacitor. Their temperatures were monitored by thermocouples or on-die temperature sensors.

The ASTM D 2809 test method, “Standard Test Method For Cavitation Corrosion and Erosion-Corrosion Characteristics of Aluminum Pumps With Engine Coolants” was first published in 19691. The method involves a copper-pipe circuit through which coolant solution, heated to 113°C, is pumped at 103 kPa for 100 hours. The method was modified to change the pump used in the test in 1989. It was updated in 1994 to accommodate a change in the cleaning procedure and was subsequently reapproved by the ASTM D-15 Committee on Engine Coolants in 1999.2 Tests recently conducted on several modern coolants have produced “failing” results, but the coolants are performing well in the field. Further, the repeatability and reproducibility of the method have been questioned. A round-robin series of tests sponsored by the Ford Motor Company revealed significant variations and cause for concern.

Mist generated from water-soluble fluids used in machining operations represents a potentially significant contribution to worker exposure to airborne particles. Part I of this study [1], discussed polymer additives as mist suppressants for straight mineral oil metalworking fluids (MWF), which have been successfully employed at several locations. This paper focuses on recent developments in polymer mist suppressants for water-based MWF, particularly in the production environment. The polymer developed and tested in this study functions on a similar basis to that for straight oil anti-mist additives. This water soluble polymer suppresses the formation of small mist droplets and results in a distribution of larger droplet sizes. These larger droplets tend to settle out near the point of machining, resulting in a significant decrease in the total airborne mist concentration.

Trapped air bubbles inside coolant systems have adverse effect on the cooling performance. Hence, it is imperative to ensure an effective filling and de-aeration of the coolant system in order to have less air left before the operation of the coolant system. In the present work, a coolant/air multiphase VOF method was utilized using the commercial CFD software SimericsMP+® to study the coolant filling and subsequent de-aeration process in a Battery Electric Vehicle (BEV) cooling system. First, validations of the numerical simulations against experiments were performed for a simplified coolant recirculation system. This system uses a tequila bottle for de-aeration and the validations were performed for different coolant flow rates to examine the de-aeration efficiency. A similar trend of de-aeration was captured between simulation and experimental measurement.

In an automotive cooling circuit, the wax melting process determines the net and time history of the energy transfer between the engine and its environment. A numerical process that gives insight into the mixing process outside the wax chamber, the wax melting process inside the wax chamber, and the effect on the poppet valve displacement will be advantageous to both the engine and automotive system design. A fully three dimensional, transient, system level simulation of an inlet controlled thermostat inside an automotive cooling circuit is undertaken in this paper. A proprietary CFD algorithm, Simerics-Sys®/PumpLinx®, is used to solve this complex problem. A two-phase model is developed in PumpLinx® to simulate the wax melting process. The hysteresis effect of the wax melting process is also considered in the simulation.

The deionized water/ethylene glycol coolant used in the Ford Focus Fuel Cell Vehicle (FCV) requires very low conductivity (< 5 μS/cm) to avoid current leakage and short circuiting, presenting a unique water chemistry issue. The coolant's initially low conductivity increases as: 1) ions are released from system materials through leaching, degradation and/or corrosion, and 2) organic acids are produced by ethylene glycol degradation. Estimating the leaching potential of these ions is necessary for design and operation of fuel cell vehicles. An on-board mixed-bed, ion exchange resin filter is used to maintain low conductivity by removing leached or produced ions. Various candidate materials were evaluated for leaching potential by exposing them to coolant at the design operating temperature for several months and periodically analyzing the coolant for ions.

A cooling fan is an essential device of the engine cooling system which is used to remove the heat generated inside the engine from the system. An essential element for successful fan designs is to evaluate the pressure over the fan blade since it can generate annoying noices, which have a negative impact on the fan’s performance and on the environment. Reducing the acoustic surface power will assist in building improved designs that comply with standards and regulations in achieving a more quiet environment. The usage of computational fluid dynamics (CFD), with support of mesh morphing, can provide simulation study for optimizing the shape of a fan blade to reduce the aeroacoustic effects. The investigation process will assist in examining and analyzing the acoustic performance of the prototype, impact of different parameters, and make a solid judgement about the model performance for improvement and optimization.

A continuous demand for added multimedia features in the automotive audio systems not only requires adequate cooling of the internal electronics, but also the media itself. Thermal engineers focus their efforts only on keeping the electronics below thresholds by conventional methods such as internal fans, heat sinks, etc., while overlooking the CD media. The environment within the instrument panel (IP) poses additional challenge in maintaining the media at a temperature level that is comfortable to the human touch. Fans that would be a natural choice in such situations, could cause noise audible to the customer and thus create a new problem. A solid-state cooling device that uses Thermoelectric coolers (TEC) is proposed to keep the CD temperature low. The system comprises of TECs assembled with the hot side attached to a heat sink and the cold side attached to the radio top surface.

Compact heat exchangers are commonly used in diesel engines to reduce the temperature of recirculated exhaust gases, resulting in decreased NOx emissions. These exhaust gas recirculation (EGR) coolers experience fouling through deposition of particulate matter (PM) and hydrocarbons (HCs) that reduces the effectiveness of the cooler. Surrogate tubes have been used to investigate the impacts of gas flow rate and coolant temperature on the deposition of PM and HCs. The results indicate that mass deposition is lowest at high flow rates and high coolant temperatures. An oxidation catalyst was investigated and proved to effectively reduce deposition of HCs, but did not reduce overall mass deposition to near-zero levels. Speciation of the deposit HCs showed that a range of HCs from C15 - C25 were deposited and retained in the surrogate tubes.

An engine cooling system in an automotive vehicle comprises of heat exchangers such as a radiator, charge air cooler and oil coolers along with engine cooling fan. Typical automotive engine-cooling fan assembly includes an electric motor mounted on a shroud that encloses the radiator core. One of main drivers of fan shroud design is Noise, Vibration, and Harshness (NVH) requirements without compromising the main function of airflow for cooling requirements. In addition, there is also a minimum stiffness requirement of fan shroud which is often overlooked in arriving at optimal design of it. Low Speed Damageability (LSD) assessment of an automotive vehicle is about minimizing the cost of repair of vehicle damages in low speed crashes. In low speed accidents, these fan motors are subjected to sudden decelerations which cause fan motors to swing forward thereby damaging the radiator core. So designing fan shroud for low speed damageability is of importance today.

Near Dry or Minimum Quantity Lubrication (MQL) Machining eliminates conventional flood coolant from the machining processes. In doing so, MQL reduces oil mist generation, biological contamination of coolant, waste water volume, costs for capital equipment and regulatory permitting. MQL also improves recycling and transport of coolant contaminated chips [1]. Although MQL machining technology has several advantages compared to wet machining, widespread implementation will require a paradigm shift among end-users, machine suppliers, and cutting tool suppliers. Successful implementation of MQL machining requires a high technical understanding and a solid infrastructure to support maintenance and on-going continuous improvement [2].

Recent fuel cost increases have changed engine cost/benefit design guidelines and, therefore, renewed interest in engine friction reduction. At a typical part throttle engine operating condition, the mechanical friction (including oil pump & water pump) of a conventional four-cylinder engine consumes approximately 22% of the indicated power. A1 psi (6.9 kPa) MEP reduction in mechanical friction can result in an EPA, M-H fuel economy improvement of l%-2%, depending on the engine/vehicle configuration. This paper reviews various friction measurement methods and presents motoring friction data for several small engines (four and six cylinder). The friction of various components, including the valve train, pistons, rings and rods, seals and engine auxiliaries (alternator, water pump and oil pump) are also shown. Component design modifications for reducing friction are discussed, and projections and measurements of fuel economy gains for improved components are presented.

Jet pumps are a viable option of pumping fluid if a pressurized flow stream is available as an energy source. For a Ford engine cooling circuit an effort was undertaken to improve an existing (conventional) jet pump design which could not meet the more demanding pumped flow requirements. Various virtual jet pump designs were analyzed using 3D CFD where the pumped flowrate was used to evaluate the effectiveness of the design. It was found that the existing design could not be modified to provide the needed pumped flow rate. It was decided to forgo the current design and develop a completely new configuration. This effort produced many design variances which were evaluated and resulted in a final design that closely achieved the pumped flow rate requirements. As new designs were evaluated through the process, particular geometrical aspects were observed to induce flow characteristics which improved the pumped flow performance.

Ensuring durability is one of the key requirements while developing cooling modules for various powertrains. Typically, road surface induced loads are the main driving force behind mechanical failures. While developing the components, road load accelerations are utilized in CAE simulations to predict the high-stress regions and estimate the fatigue life of the components mounted on the body. In certain scenarios where components are mounted to the body and attached to the engine with hoses, the components can experience additional loads associated with engine vibration. This attachment scheme requires a different analysis methodology to determine fatigue life. In the proposed paper, we look at the effect of engine motion (EM) on the fatigue life of internal transmission oil cooler (ITOC) which is mounted on the body through radiator and is simultaneously connected to the engine using a steel pipe. We propose a new CAE methodology taking into account the engine motion displacements.