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Drivetrain electrification is increasing in the kart racing sector since noise emissions are an important factor in urban areas. To improve range, it has become necessary to optimize the rolling resistance of kart racing tires. This paper introduces a parameter study for small bias-ply tires which are used in kart racing and investigates the effect of these parameters on rolling resistance. In recent literature, rolling resistance is mostly examined in radial passenger car tires. Most testing devices are limited to rim sizes from ten inches upwards. In this study, a test rig was developed with focus on low cost and small rim sizes. This self-developed test rig was validated through a comparison with an approved test rig according to ISO 18164 standard. A parameter study was conducted to investigate the effect of changes in the construction of the tire. These changes affect the warp count of the carcass fabric and the crown angle of the different plies.

This paper introduces a finite element (FE) approach to determine tire deformation and its effect on open-wheeled racecar aerodynamics. In recent literature tire deformation was measured optically. Combined loads like accelerating at corner exit are difficult to reproduce in wind tunnels and requires several optical devices to measure the tire deformation. In contrast, an FE approach is capable of determining the tire deformation in combined load states accurately. The FE tire model was validated using computer tomography images, 3D scan measurements, contact patch measurements and stiffness measurements. The deformed shape of the FE model was used in a computational fluid dynamics (CFD) simulation. A sensitivity study was created to determine the effect of the tire deformation on aerodynamics for unloaded and loaded tires. In addition, the influence of these tire deformations was investigated in a CFD study using a full vehicle model.

This paper introduces an improved design for pressure wave superchargers used in recreational vehicles (RV) such as motorbikes or snowmobiles equipped with smaller engines. A pressure wave supercharger (PWS), commonly known as Comprex (or Hyprex), is generally used to lower the emissions. Additionally, in comparison to a standard turbocharger (TC) system, a PWS system demonstrates superior torque response behavior. However, a major disadvantage of the Comprex are its high noise emissions and expensive manufacture. For this reason, the goal of this study was to eliminate these shortcomings and to propose a new design for a pressure wave supercharger, which is simple and relatively inexpensive to produce. In this paper, the conceptual design development of this new type of PWS is presented. The methods used were the evaluation of an existing Comprex’s design and computational fluid dynamics (CFD) simulations.