Thermal contact conductance is an important factor in a variety of applications, largely because many physical systems contain a mechanical combination of. Thermal contact resistance thermal contact conductance. Thermal contact resistance of metallic composite pair article pdf available in international journal of engineering management and economics 42. Fea based design and thermal contact conductance analysis. Effect of pressure on thermal conductance of contact joints. If an internal link led you here, you may wish to change the link to point directly to. Ways of increasing thermal conductance have been sought for situations where maximum heat dissipation is required. Technical note presenting tests conducted to determine the factors influencing the thermal conductance across the interface formed between stationary plane surfaces of 75st6 aluminumalloy and aisi type 416 stainlesssteel blocks. Also, developed a new technique for predicting thermal contact conductance in practical engineering applications which utilized a pressure measuring film that provided information about the contact pressure distribution. The lack of heat transfer through convection enforces the need for full understanding of thermal contact conductance, and the in uencing physical parameters.
Madhusudana, thermal contact conductance, springerverlag, isbn 0387945342, 1995. Heat transfer between two bodies in thermal contact is of fundamental. Despite substantial theoretical studies of thermal contact conductance in the past, the application of statistical mechanics in this field has never been attempted. Heat transfer between contacting surfaces is an important factor in the thermal behaviour of engineering components in turbomachinery and various other areas of technology. Thermal contact conductance tcc is a parameter that quantifies this heat flow. Thermal contact conductance mechanical engineering series kindle edition by madhusudana, chakravarti v download it once and read it on your kindle device, pc, phones or tablets. Thermal contact conductance, book by chakravarti v. Madhusudana, thermal contact conductance, 1996, springer. The thermal conductance is expressed in terms of the thermal conductivities of the metals and of the fluid filling the voids, the real area in contact, the number of contact points per unit area. Determining thermal contact conductance in bolted joints is a major challenge when designing for space application. Thermal interface conductance of realistic bolted joints. The new thermal contact mikic elastic correlation, is based on the heat transfer handbook, a. The work covers botha theoretical and practical aspects of thermal contact conductance. Thermal contact conductance metal surfaces air engineers.
Thermal contact conductance and its dependence on load cycling. The theoretical discussion focuses on heat transfer through spots, joints, and surfaces, as well as the role of interstitial materials both planned and inadvertent. Thermal gap conductance of conforming surfaces in contact j. The above conclusions suggest that future work on thermal contact conductance should vol. Aug 23, 2016 the work covers both theoretical and practical aspects of thermal contact conductance. Investigation of thermal contact gas gap conductance using. Thermal contact conductance of nominally flat surfaces yuncu 27. Study of thermal contact resistance of rough surfaces based on the. In thermal engineering, the thermal contact conductance wm 2. When components are bolted or otherwise pressed together, a knowledge of the thermal performance of such joints are also needed. Heat transfer august, 1993 heat transfer at aluminumwater interfaces. Ways of increasing thermal conductance have been sought for situations where maximum heat dissipation is. An integrated experimental and numerical investigation of the thermal contact resistance across two nominally flat, coated metallic engineering surfaces in contact is presented.
Contact resistance measurement and its effect on the thermal. The improvement gained by insertion of the goldcoated aluminum washer between the contact surfaces was essentially offset by the addition of two extra contact interfaces. It is shown that at these pressures conduction through the. This book covers both theoretical and practical aspects of thermal contact conductance. Pdf a unique experimental setup was fabricated to carry out axial heat flow steady state experiments for the. Prediction of thermal contact conductance in vacuum by. The practical discussion includes formulae and data that can be used in designing heattransfer equipment for a variety of joints, including. T where h is the total joint conductance, q is the total heat transfer across the interface and a is the apparent area and.
Measurement and prediction of thermal contact resistance. Thermal contact conductance of some metal surfaces in air from various sources. Use features like bookmarks, note taking and highlighting while reading thermal contact conductance mechanical engineering series. The thermal model predicts the thermal contact conductance for a given set of contact parameters, which are the shape, mean size, and number of contact spots. Thermal contact conductance ebook by chakravarti v. Thermal contact conductance and rectification at low joint. The theoretical discussion covers heat transfer through spots, joints, and surfaces, as well as the role. With assumptions of a particular statistical distribution of surface parameters, as well as a mode of deformation for contacting asperities, contact conductance is predicted for given material properties and applied.
A swvey of the thermal conductance of metallic contacts. More recent attempts at predicting thermal contact conductance at an interface, especially focusing on the low. Thermal contact conductance plays an important role in all thermal systems where a mechanical contact is involved. Most experimentally determined values of the thermal contact resistance fall between 0. Control of thermal contact conductance using interstitial. Madhusudana 22 demonstrated that in many applications involving contact heat transfer, including electronic components, the contact pressure is low or moderate. The thesis investigates thermal contact resistance of a. The model consists of a surface deformation computation, which determines the actual contact area and number of contacting asperities at a joint, and a constriction resistance analysis, which determines the. Concluded that contact conductance improves in the presence of a conducting medium. Fea based design and thermal contact conductance analysis of. To analyse the thermal contact conductance in application relevant to saab ab an. The prediction of thermal contact conductance inverse of resistance is commonly accomplished by semiempirical correlations. Heat transfer between two bodies in thermal contact is of fundamental importance in a wide variety of applications ranging from industrial and domestic processes to fundamental biology and chemistry. Accuracy in thermal contact conductance experiments madhusudana.
Thermal contact conductance mechanical engineering series 2. Thermal interface conductance of realistic bolted joints in. The theoretical discussion focuses on heat transfer. The magnitude of the contact conductance is a function of a number of parameters including the thermophysical and mechanical properties of the materials in contact, the characteristics of the contacting surfaces, the presence of gaseous or nongaseous interstitial media, the apparent contact pressure, the mean junction temperature, and the conditions surrounding the junction, as noted by. Of particular interest is the work presented by fenech and roshsenow ref. May 23, 2012 high temperature contact conductance measurement across cylindrical joint by the periodic method. Thermal contact conductance mechanical engineering series. This disambiguation page lists articles associated with the title thermal conductance. One may observe that the heat flow is directly related to the thermal conductivities of the bodies in contact, and, the contact area, and the thermal contact resistance, which, as previously noted, is the inverse of the thermal conductance coefficient. The contact parameters are obtained using a particular deformation model and a geometry model. Thermal contact, conductance, fea, roughness, modeling. Introduction the prediction of the coefficient of thermal contact conductance across metallic joints under load has received much attention during the past two decades, as indicated by references 1 to 17. Fletcher thermal contact conductance is highly important in a wide variety of applications, from the cooling of electronic chips to the thermal management of spacecraft.
Thermal contact resistance is significant and may dominate for good heat conductors such as metals but can be neglected for poor heat conductors such as insulators. Madhusudana 1974 2 found out the effect of interface fluid on thermal contact resistance. An approach is proposed to predict the thermal contact resistance tcr of rough surfaces. Thermal contact conductance at low contact pressures. Thermal contact resistance of metallic composite pair. Thermal contact conductance and its dependence on load. Due to the uncertain variance of pressure distribution in a bolted. Thermal contact conductance of composite cylinders an.
Contact resistance measurement and its effect on the. The work covers both theoretical and practical aspects of thermal contact conductance. Madhusudana, thermal contact conductance, second edition, springer. Kw represents the heat conduction between two solid bodies. This paper addresses contact conductance from macroscopic and microscopic viewpoints in order to demonstrate the promise of the statistical mechanics approach. The types of joints investigated included bare metaltometal contact, contact surfaces separated by a good conductor brass, and contact surfaces separated by a. Madhusudana cv 2000 accuracy in thermal contact conduct. Thermal contact conductance is the ability to conduct heat between two solid bodies when they are in thermal contact and inverse property of thermal contact conductance is called thermal contact resistance. Thermal contact conductance of demountable in vacuum. Similarly, the default thermal contact coopermikicyovanovich cmy plastic correlation is also derived from the wiley handbook. Correlations for the thermal contact conductance, which is the inverse of contact resistance, as a function of fin number, fin thickness, net interference, and tube diameter were presented in both papers. Sep 24, 20 li yz, madhusudana cv, leonardi e 2000 enhancement of thermal contact conductance.
In figure 4, thermal conductance of copper contact pairs. Lewis research center summary a simplified approximate method for calculating the coefficient of thermal contact conductance has been derived. Pdf experimental investigation of thermal contact conductance for. Heat transfer engineering thermodynamics engineering physics. Effect of pressure on thermal conductance of contact. This book covers both the theoretical and practical aspects of thermal contact conductance. Contact resistance could be as high as 55% of overall resistance. Jan 26, 2005 since many of the motivating applications involve contacting spheres and since there has been a limited number of contact resistance studies on spheres undergoing elastic deformation, the objective of this study is to obtain measurements of the contact resistances between metallic spheres in elastic contact, as well as to quantify their. The theoretical discussiona focuses ona heat transfer through spots, joints, and surfaces, as well as the role of interstitial materials both planned and inadvertent.
Prediction of thermal contact resistance electronics cooling. Thermal contact conductance in aircraft applications diva. Thermal contact conductance between solid interfaces under. It can be formulated as 2 qa t q t r c 4 the reciprocal of thermal contact resistance is termed as thermal contact c o ndu ctance.