An inverse method for estimating heat sources in a high speed spindle

2016 ◽  
Vol 105 ◽  
pp. 65-76 ◽  
Author(s):  
Jin-Huang Huang ◽  
Van-The Than ◽  
Thi-Thao Ngo ◽  
Chi-Chang Wang
Author(s):  
Thi-Thao Ngo ◽  
◽  
Chi-Chang Wang ◽  
Ming-Lun Chang ◽  
Van-The Than ◽  
...  

Thermal has significantly effect on high speed machine tools. When temperature growing up, it often causes processing errors and further reduces product quality. This paper aims to investigate magnitude of heat sources and temperature distribution in a horizontal lathe based on inverse method. In present thermal model, there is not only consideration of spindle but also analyzing relative structures. Simulated and experimental temperatures are used as input data to predict heat sources and temperature field. Effects of speed, number measured points, measurement errors and measured distance on predicted results are analyzed. Results indicate that this inverse method can accurately estimate the heat sources based on two measured temperatures at front and rear outer rings. The trend of estimated heat sources is then compared to measured load rate. Results herein are useful information for designing horizontal lathe spindle and reducing thermal errors.


2018 ◽  
Vol 54 (5A) ◽  
pp. 238
Author(s):  
Ngo Thi Thao

A combination of finite element and conjugate gradient methods to establish an inverse method for estimating heat sources as well as temperatures of a micro high speed motorized spindle is presented in this article. The proposed method is simple in constructing the direct problem by using COMSOL software. Experiment setup and measurement process are introduced. Results show that inverse solutions agree with experimental data based on temperatures at only one measurement point. Influence of speed on heat sources and temperatures is indicated. Temperature distribution in the spindle is also given and discussed. From these findings, it can be said that the proposed method is appropriated for inversely determining the heat source in micro high speed motorized spindle. The obtained results provide useful information to estimate thermal deformation.


Author(s):  
Marcin Lefik ◽  
Krzysztof Komeza ◽  
Ewa Napieralska-Juszczak ◽  
Daniel Roger ◽  
Piotr Andrzej Napieralski

Purpose The purpose of this paper is to present a comparison between reluctance synchronous machine-enabling work at high internal temperature (HT° machine) with laminated and solid rotor. Design/methodology/approach To obtain heat sources for the thermal model, calculations of the electromagnetic field were made using the Opera 3D program including effect of rotation and the resulting eddy current losses. To analyse the thermal phenomenon, the 3D coupled thermal-fluid (CFD) model is used. Findings The presented results show clearly that laminated construction is much better from a point of view of efficiency and temperature. However, solid construction can be interesting for high speed machines due to their mechanical robustness. Research limitations/implications The main problem, despite the use of parallel calculations, is the long calculation time. Practical implications The obtained simulation and experimental results show the possibility of building a machine operating at a much higher ambient temperature than it was previously produced for example in the vicinity of the aircraft turbines. Originality/value The paper presents the application of fully three-dimensional coupled electromagnetic and thermal analysis of new machine constructions designed for elevated temperature.


Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1871
Author(s):  
Xinlu Yu ◽  
Yingqian Fu ◽  
Xinlong Dong ◽  
Fenghua Zhou ◽  
Jianguo Ning

The dynamic constitutive behaviors of concrete-like materials are of vital importance for structure designing under impact loading conditions. This study proposes a new method to evaluate the constitutive behaviors of ordinary concrete at high strain rates. The proposed method combines the Lagrangian-inverse analysis method with optical techniques (ultra-high-speed camera and digital image correlation techniques). The proposed method is validated against finite-element simulation. Spalling tests were conducted on concretes where optical techniques were employed to obtain the high-frequency spatial and temporal displacement data. We then obtained stress–strain curves of concrete by applying the proposed method on the results of spalling tests. The results show non-linear constitutive behaviors in these stress–strain curves. These non-linear constitutive behaviors can be possibly explained by local heterogeneity of concrete. The proposed method provides an alternative mean to access the dynamic constitutive behaviors which can help future structure designing of concrete-like materials.


2013 ◽  
Vol 579-580 ◽  
pp. 568-572
Author(s):  
Da Guo Ma ◽  
Xin Bo Jiang

The structure and composition of the air-cooled high speed motorized spindle for wood-working machine and some features relative to the metal cutting motorized spindle are introduced briefly. Then the main heat sources and heat dissipation mechanism of the air-cooled motorized spindle are thoroughly analyzed, finite element model of the air-cooled motorized spindle is built, the motorized spindles temperature distribution under thermal steady state and the influence of speed are analyzed. The results show that air cooling relative to the water or oil cooling has many advantages and reasonable heat dissipation structure design of air-cooled motorized spindle could meet the requirements of the high-speed motorized spindle for wood-working machine.


Sensors ◽  
2019 ◽  
Vol 19 (11) ◽  
pp. 2481 ◽  
Author(s):  
Ashraful Islam ◽  
Adam L. Houston ◽  
Ajay Shankar ◽  
Carrick Detweiler

Traditional configurations for mounting Temperature–Humidity (TH) sensors on multirotor Unmanned Aerial Systems (UASs) often suffer from insufficient radiation shielding, exposure to mixed and turbulent air from propellers, and inconsistent aspiration while situated in the wake of the UAS. Descent profiles using traditional methods are unreliable (when compared to an ascent profile) due to the turbulent mixing of air by the UAS while descending into that flow field. Consequently, atmospheric boundary layer profiles that rely on such configurations are bias-prone and unreliable in certain flight patterns (such as descent). This article describes and evaluates a novel sensor housing designed to shield airborne sensors from artificial heat sources and artificial wet-bulbing while pulling air from outside the rotor wash influence. The housing is mounted above the propellers to exploit the rotor-induced pressure deficits that passively induce a high-speed laminar airflow to aspirate the sensor consistently. Our design is modular, accommodates a variety of other sensors, and would be compatible with a wide range of commercially available multirotors. Extensive flight tests conducted at altitudes up to 500 m Above Ground Level (AGL) show that the housing facilitates reliable measurements of the boundary layer phenomena and is invariant in orientation to the ambient wind, even at high vertical/horizontal speeds (up to 5 m/s) for the UAS. A low standard deviation of errors shows a good agreement between the ascent and descent profiles and proves our unique design is reliable for various UAS missions.


2012 ◽  
Vol 723 ◽  
pp. 14-19 ◽  
Author(s):  
Zhan Qiang Liu ◽  
Fan Zhang ◽  
Fu Lin Jiang

In high speed machining, temperature distribution in workpiece is the main factor which directly affects the surface integrity and dimensional accuracy of machined workpiece. In this paper, the machined workpiece temperature in high speed peripheral milling is analyzed through using moving heat source method and inverse method. Firstly, the workpiece to be machined is considered as a semi-infinite solid to model the transient surface temperature using arc-shaped moving heat source. Inverse method is then applied for the calculating of heat flux. Peripheral milling experiments of 1045 steel is performed with coated carbide insert The machined surface temperatures were measured during experiments. The measured results were found to be in agreement with the predicted ones by transient models for machined surface temperatures. These results confirm the conclusion that the transient workpiece temperature will decline when the cutting speed increases to a critical value.


Author(s):  
W. T. Tiow ◽  
M Zangeneh

The development and application of a three-dimensional inverse methodology in which the blade geometry is computed on the basis of the specification of static pressure loading distribution is presented. The methodology is based on the intensive use of computational fluid dynamics (CFD) to account for three-dimensional subsonic and transonic viscous flows. In the design computation, the necessary blade changes are determined directly by the discrepancies between the target and initial values, and the calculation converges to give the final blade geometry and the corresponding steady state flow solution. The application of the method is explored using a transonic test case, NASA rotor 67. Based on observations, it is conclusive that the shock formation and its intensity in such a high-speed turbomachinery flow are well defined on the loading distributions. Pressure loading is therefore as effective a design parameter as conventional inverse design quantities such as static pressure. Hence, from an understanding of the dynamics of the flow in the fan in relation to its pressure loading distributions, simple guidelines can be developed for the inverse method in order to weaken the shock formation. A qualitative improvement in performance is achieved in the redesigned fan. The final flowfield result is confirmed by a well-established commercial CFD package.


Author(s):  
Moaine Jebara ◽  
Sofiane Belhabib ◽  
Lionel Boillereaux ◽  
Michel Havet ◽  
Alain Sarda ◽  
...  

This work describes the implementation of a simple procedure that helps to easily position the heating elements in press plates used in high-temperature composites thermoforming process. The developed method permits to obtain desired temperature profiles on the surface of the press plates through two main steps. The first step consists in finding out an appropriate parametric curve that defines the spatial location of the heating sources into the thickness of the press heating plates. The second step uses an inverse method that combines a stochastic optimization algorithm in conjunction with finite element simulations. This second step serves for the adjustment of the position curve parameters to obtain a simulated temperature profile as close as possible to the expected one at the press plates surface. This easy-to-implement approach is shown to be very effective to rapidly obtain a suitable location of the heat sources that minimizes energy consumption.


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