## 1 Introduction  
An excessive in temperature due to heat generation during the cutting process is an important issue that not only accelerates tool wear but also affects machining accuracy and surface quality of the finished workpieces [1]. Therefore, the research on active control of cutting temperature via promotion of heat-dissipation is indispensable for a highly reliable machining process. Wet machining using different kinds of cutting fluids is a most widely used technique to maintain the cutting temperature below some specified optimal cutting temperatures [2]. However, the excessive use of cutting fluids becomes a major problem owing to some associated economic, environmental and health concerns [3]. Dry machining can be considered as a feasible approach to eliminate the use of cutting fluids because of low processing cost and soft ecological hazard [4]. Compared with wet machining, dry cutting shows some superiority such as lower thermal shock and improved useful life of cutting tools, however, the machining friction and the cutting temperature during dry machining are usually greater than those of wet machining. Temperature has an impact on tool wear, thus it is important for the cutting process [5; 6]. Aiming at achieving better temperature reduction performance in dry machining process, researchers have proposed a variety of methods and achieved some meaningful results. [PERSON] [7] and [PERSON] [8] investigated the utilization of CO\({}_{2}\) and liquid nitrogen as cooling media to reduce the cutting temperature and reported good improvements. On the other hand, heat pipe cooling is also a widely utilized method to improve cutting performances and has attracted significant attentions [9; 10]. Regarded as an indirect cooling system (ICS), research on the internal cooling system has already been a hot topic in industry because of its convenient installation for conventional machine tools. Since the initial description of this type of cooling system in the 1970s, a variety of improvements have been proposed. [PERSON] designed an internally cooled cutting tool consisting of a modified cutting insert, cooling adapter accommodating micro-channel, and tool-holder with inlet and outlet ports [11]. [PERSON] created a modified tool-holder with an internally cooled tool to enhance the heat transfer [12]. In these two studies, pyrometers were employed to monitor the rise of cutting temperature and evaluate the enhancement of cooling effect. [PERSON] presented an enclosed internal cooling circuit in the support seat [13], and in his study, a thermal imager was employed to measure cutting temperatures in the machining process. Among the above reported literature, research on ICS mainly focuses on modifications of tool-holder forms, support seat or the insert. These methods above can indeed be improved, however they usually require additional supply devices that inevitably increase the complexity of the machining tool or modify the machine tool structure, significantly limiting industrial applications. Considering the pros and cons of the above cooling methods, in this paper, a novel independent cooling system based on an internal cooling fluid channel is devised and applied to promote heat dissipation during cutting process. A distinct advantage of this novel ICS lies in its simplified mechanical structure and high heat dissipation-promoting performance. Compared with traditional ICS, the proposed independent internal cooling system needs only limited modification for the cutting component and the cooling media can also be replaced by the existing refrigerating system. The heat-energy balance equations of the cooling structure are established to evaluate the cutting temperature. Temperature fields on the rake face and on the flank face were simulated on the numerical platform of Ansys CFX (12.1, ANSYS, Inc., Canonsburg, PA, USA, 2009). Moreover, turning tests were carried out to verify the validation of the numerical model which was previously put forward.