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Investigations of low drag shapes for passenger vehicles were conducted in the 1930s but production cars of today have yet to approach the potential drag coefficients shown by that early research. Furthermore, the adoption of low drag styles has been resisted because of a perception of compromise to the exterior style and so recent aerodynamic developments have concentrated on changes to non-styled surfaces. However, environmental and ecological pressures are placing increasing demands on manufacturers to produce energy efficient vehicles and the contribution of aerodynamics in that equation is increasing, particularly with the adoption of technologies such as regenerative braking and measurements being made using more real-world use driving cycles. Relying on non-styled surfaces alone for drag reduction is unlikely to be sufficient to deliver the improvements required.

With the ever increasing demand on automotive manufactures to reduce lead times, improve performance, add air conditioning, meet noise and pollution legislation the need to evaluate and improve cooling system performance at the design stage is becoming increasingly important. The cooling system is taken to encompass the full air path of grills, inlet plenum, cooling pack, under bonnet resistance and outlet to the free stream. This paper describes the main structure of a PC based computer program which is being developed to permit the cooling system performance to be optimized at the vehicle concept stage or prior to major updates to a model, which could be for example front end styling or a change of engine. Also discussed are details of how the air paths through the cooling pack, and the system resistances from the inlet grill to the engine compartment outlet are determined.

In aftertreatment system design, flow uniformity is of paramount importance as it affects aftertreatment device conversion efficiency and durability. The major trend of downsizing engines using turbochargers means the effect of the turbine residual swirl on the flow needs to be considered. In this paper, this effect has been investigated experimentally and numerically. A swirling flow rig with a moving-block swirl generator was used to generate swirling flow in a sudden expansion diffuser with a wash-coated diesel oxidation catalyst (DOC) downstream. Hot-wire anemometry (HWA) was used to measure the axial and tangential velocities of the swirling flow upstream of the diffuser expansion and the axial velocity downstream the monolith. With no swirl, the flow in the catalyst monolith is highly non-uniform with maximum velocities near the diffuser axis. At high swirl levels, the flow is also highly nonuniform with the highest velocities near the diffuser wall.

The emergence of additive manufacturing (AM) technology has enabled the internal cooling channel layout for high pressure aluminium die casting (HPADC) tools to be designed and modified without topological constraint. Optimisation studies of a full industrial HPADC mould for extending the tool service life has received limited attention due to the high geometrical complexity and the various physics with multi time- and length- scales in addition to the manufacturability limitations. In this work, a new computationally efficient algorithm that employs the adjoint optimisation method has been developed to optimise the coolant channels layout in a complete mould with various 3D printed inserts. The algorithms significantly reduced the computational time and resources by decoupling the fluid flow in the coolant channels from the tool and simulating them separately.

Automotive recycling within Europe increased with the analysis of the environmental focus of automotive products and their product system [1], which is reflected within Europe in new legislation governing the recyclability of vehicles. This paper presents a new tool for evaluating automotive recyclability in the design process, within a whole life cost methodology. The developed business model approach reviews automotive design practices and has adapted life cycle analysis techniques to give special consideration for recyclability and costing of alternative automotive design strategies. Engineering designers can utilise the business model approach to design and manufacture a more recyclable vehicle and incorporates the economic viability of the recycling process of a product or component at the design stage. This paper presents one example where the increasing complexity of product design can produce economic justifications for design for recycling.

The potential benefit for vehicles travelling in ‘platoon’ formations arises from a reduction in total aerodynamic drag which can result from the interaction of bluff bodies in close-proximity. During the 1980s this was considered as an opportunity to alleviate congestion and also for fuel-saving in response to the fuel crises of the 1970s. Early interest was limited partly due to the level of available control technology. But recent developments in vehicle-to-vehicle communication systems and autonomous driving technologies have provided the potential for platooning to be incorporated within future traffic management systems prompting renewed interest. For the investigation described in this paper, a new passenger car model was designed as the basis for determining the effectiveness of future low-drag styles in platoon formations. Small-scale models were tested in the Coventry University Wind Tunnel in platoons of up to 5 vehicles.

Additive manufacturing (AM) provides significant geometric design freedom for the cooling of high pressure die casting (HPDC) tools. Designing cooling channels that can achieve a uniform temperature throughout the tool-cast interface during the moulding process can limit part warping and sink marks, internal part stresses, and increase tool life. However, the design of the embedded cooling channels requires high computational resources to model the heat transfer process for the cast, mould, and coolant from the moment aluminium is injected into the cavity until the injection for the next cycle. To enable the examination of the effect of various parameters, a simplified 3-D CFD conjugate heat transfer model is introduced by considering the experimental observations. The model decouples the cast part from the mould.

The porous medium approach is widely used to represent high-resistance devices, such as catalysts, filters or heat exchangers. Because of its computational efficiency, it is invaluable when flow losses need to be predicted on a system level. One drawback of using the porous medium approach is the loss of detailed information downstream of the device. Correct evaluation of the turbulence downstream affects the calculation of the related properties, e.g. heat and mass transfer. The novel approach proposed in the current study is based on a modified distribution of the resistance across the porous medium, which allows to account for the single jets developing in the small channels, showing an improved prediction of the turbulence at the exit of the device, while keeping the low computational demand of the porous medium approach. The benefits and limitations of the current approach are discussed and presented by comparing the results with different numerical approaches and experiments.

This study presents a one-dimensional model for the prediction of the pressure loss across a wall-flow gasoline particulate filter (GPF). The model is an extension of the earlier models of Bissett [1] and Konstandopoulos and Johnson [2] to the turbulent flow regime, which may occur at high flow rates and temperatures characteristic of gasoline engine exhaust. A strength of the proposed model is that only one parameter (wall permeability) needs to be calibrated. An experimental study of flow losses for cold and hot flow is presented, and a good agreement is demonstrated. Unlike zero-dimensional models, this model provides information about the flow along the channels and thus can be extended for studies of soot and ash accumulation, heat transfer and reaction kinetics.

The potential benefit for passenger cars when travelling in a ‘platoon’ formation results from the total aerodynamic drag reduction which may result from the interaction of bluff bodies in close-proximity. In the 1980s this was considered as an opportunity to alleviate congestion and also for fuel-saving in response to the oil crises of the 1970s. Early interest was limited by the availability of suitable systems to control vehicle spacing. However, recent developments in communication and control technologies intended for connected and autonomous driving applications has provided the potential for ‘platooning’ to be incorporated within future traffic management systems. The study described in this paper uses a systematic approach to changes in vehicle shape in order to identify the sensitivity of the benefits of platooning to vehicle style.

Lithium-ion batteries (LiBs) have been widely used in electrified vehicles, and the battery thermal management (BTM) system is needed to maintain the temperature that is critical to battery performance, safety, and health. Conventionally, three-dimensional battery thermal models are developed at the early stage to guide the design of the BTM system, in which battery thermophysical parameters (radial thermal conductivity, axial thermal conductivity, and specific heat capacity) are required. However, in most literature, those parameters were estimated with greatly different values (up to one order of magnitude). In this paper, an investigation is carried out to evaluate the magnitude of the influence of those parameters on the battery simulation results. The study will determine if accurate measurements of battery thermophysical parameters are necessary.

The work described in this paper is a continuation of an investigation into the effects of systematic changes in upper-body geometry on the aerodynamic drag of passenger-car-like bluff-body models in close longitudinal proximity and operating in platoon formations. The original work, presented in SAE paper 2019-01-0659, showed measurements of the aerodynamic drag of individual models within three-model platoons and for which each model was tested in three different upper-body configurations This provided a data-set of 27 platoon configurations to compare with the three baseline conditions of the isolated models. The work contrasted with other published platooning research in which the spacing, between homogeneous models in the platoons, was the only variable to be considered. In this publication the results of further wind tunnel tests, using the same models as before but in two-model platoons, providing a further 9 test configurations are compared with the original data.

Micro-mobility vehicles such as electric scooters and bikes are increasingly used for urban transportation; their designs usually trade off performance and range. Addressing thermal and cooling issues in such vehicles could enhance performance, reliability, life, and range. Limited packaging space within the wheels precludes the use of complex cooling systems that would also increase the cost and complexity of these mass-produced wheel motors. The present study begins by evaluating the external aerodynamics of the scooter to characterise the airflow conditions near the rotating wheel; then, a steady-state conjugate heat transfer model of a commercially available wheel hub motor (500W) is created using commercial computational fluid dynamics (CFD) software, StarCCM+. The CAD model of the motor used for this analysis has an external rotor permanent magnet (PM) brushless DC topology.

With an increasing focus on the reduction of greenhouse gases by the transport industries and continued development of connected and autonomous vehicle systems, the potential for aerodynamic drag reduction by means of managed systems of vehicles travelling in close-proximity, termed “platooning”, has continued as topic for research. Early-work in passenger-car platooning was conducted by varying the spacing between vehicles in homogeneous platoons. More recently the use of systematic changes in upper-body geometry has provided data for another variable in the assessment of platooning characteristics. The results of the investigation described in this paper adds to previously published platooning results using the Windsor reference model. For this investigation a new add-on geometry to the standard nose was designed to provide a simplified bonnet feature.

The aerodynamic effects of bodies in close proximity continues to be an interest for those involved in aeronautical, automotive and civil engineering together with those involved in sports such as cycling, motor racing and sailing. For passenger cars, research in the USA published in the 1980s had considered travelling in close proximity, termed “platooning”, as a means for reducing congestion. But the aerodynamic drag reduction and fuel-savings found in associated wind tunnel tests and road-trials became the focus of further investigations. Although practical applications were not originally pursued, the recent development of control systems for connected and autonomous vehicles has provided the opportunity for platooning to be considered again within future traffic management systems.