Thermal Simulations Based on Macro-Models

Abstract

Thermal transfer simulations, computed fluid dynamic solutions and finite element methods in general are vital sources of information about behavior of machine parts with heat loading. All these methods have common disadvantages, which include the requirements of a skilled engineer, hardware and software, and generally the high cost of computation. These problems are solved in this article. The reduction of costs is solved by a new tool, which uses simple macro-elements with predefined, parametric properties. These elements are able to describe cooling channels, heat transfers in bodies or identify the temperatures of heat sources. Computation by macro-element method takes a significantly shorter time with suitable accuracy. The macro-element method is suitable for customizing in a wide spectrum of thermal transfer cases. The article defines macro-elements, describes their implementation and the verification of the method.

Sensitivity Analysis and Validation of a Thermo-Mechanical Model of a Spindle

“…Figure 3 shows the solution setup of the computation. The heat transfer coefficients between bodies, sources of heat load and convection coefficient are defined [7], [3].…”

“…The ball bearing FAG DLR with outer diameter 360mm is defined: total surface area of balls 79150mm 2 . Simplified model is designed, 76608mm 2 surface area for convection, 5138mm 2 for contact; heat transfer coefficient 2500W/m 2 K for surface contact, forced convection area coefficient 30W/m 2 K [7]. Due to the presumed heat conduction in the shaft around 30% [12], heat permissivity of a bearing is presumed 8,5W/K.…”

“…The production accuracy of machine tools is effected by the thermo-mechanical behaviour of the components and structural design. Heat distribution and temperature is changed in time due to the time-dependent internal and external heat sources [3], [7], [10]. Generated temperature differences causes thermal induced displacements of the machine structure.…”

Parameterized Sub-systems of HVAC Piping System

“…Pipes of such large dimensions must be securely fastened to the structure. We deal with design, optimization and structural [1] and temperature [2], [3], [4], [10] numerical simulations of piping systems and supports. The design takes into account the resulting functionality and efficiency, manufacturability, assembly and safety during production and operation.…”

Determination of Cohesive Parameters for Mode I of Epoxy Adhesive

“…For joining of those composite materials with metals the adhesive bond is most frequently the best option. The advantages of adhesive bonds are that they have not Heat-affected zone (such as welding, [8], [9], [10], [20]) and they do not need to drill holes (stress concentrators) as bolted joints and riveted joints [6], [7]. Gluing is also suitable for printed composite parts [11], [12], [13].…”