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Particularly during machining, large heat sources and thus high temperature gradients and mechanical stress occur in the cutting zone. By using cutting fluids, part of the heat generated can be dissipated, thereby reducing local temperatures. To quantify the cooling efficiency of the cutting fluid, the flow behaviour of the cutting fluid in vicinity of the cutting zone must be determined to derive the resulting convective heat transfer coefficients at the tool. The purpose of this paper is to investigate the local distribution of the convective heat transfer coefficient as a function of the flow boundary conditions, specifically evaluating the effects of Reynolds number, injection angle and nozzle radius.

The geometries, temperature fields as well as the heat sources resulting during the machining process are extracted from a chip formation simulation using finite element method (FEM) and used to set up a three-dimensional computational fluid dynamics (CFD) flow simulation.

On the tool rake face, the local distribution of the convective heat transfer coefficient can be divided into three regions. Firstly, the region where the liquid impinging jet initially strikes, then a region near the chip where the flow is strongly deflected and then the remaining region in the boundary layer region. For each region, a function is derived that describes its position, subsequently the mean convective heat transfer coefficient is determined and summarised in a Nusselt correlation as a function of the flow parameters.

Simulation results reveal that the distribution of the convective heat transfer coefficient on the tool rake face can be divided into three distinct regions: the impingement zone where the impinging jet first strikes, the deflection zone near the chip where the flow sharply redirects and the boundary layer zone covering the remaining surface. A geometric function is derived to describe the position and extent of each of these areas. In addition, the mean convective heat transfer coefficient can be determined for each of the regions using a Nusselt correlation based on the flow parameters.

These correlations allow for simplified determination of the local convective heat transfer coefficient on the tool.

This paper introduces an innovative approach for estimating the local distribution of the convective heat transfer coefficient at the tool rake face during orthogonal cutting under cutting fluid supply. The influence of the three-dimensional flow field of the cutting fluid jet of the convective heat transfer coefficient on the tool rake face is analysed in detail in the vicinity of the chip as a function of varying Reynolds numbers, nozzle radii and injection angles within a three-dimensional geometry.

The purpose of this study is to draw a scientific map of the Grand Tours cycling as part of the growing research field in this field at the global level. This study also identifies the components of scientific production in this field along with their collaboration patterns.

With the aim of achieving a comprehensive and deep understanding of the studies related to the Grand Tour, this research aims to address the existing gaps and provide a comprehensive summary of these scholarly works. To achieve this goal, the authors used a systematic and scientometric combination method, analyzing studies from the past half century (1970–2022).

The research findings reveal that scientific studies related to cycling events exhibit a geographical concentration within the continent of Europe, surpassing other continents. Notably, Spain, the USA, the UK and Italy emerge as pioneers in this field of inquiry. The main themes identified in these studies encompass cycling, the Tour de France, performance, professional roa cycling, heart rate, endurance, doping and power output.

This research, along with other systematic studies, contributes to the existing literature in this field by providing both quantitative and qualitative data. Additionally, the study serves as a foundation for identifying active and influential countries, institutions and authors in this domain. Such insights are highly effective in establishing scientific focal points in this field.

This study, in conjunction with the introduction of key figures in mega cycling event research, sheds light on the thematic areas explored within these studies. Notably, it is the sole study that has illuminated hidden facets of this field using scientometric and systematic methods.