Photogrammetrically measured distortions of a composite microwave reflector system in vacuum at ~90 K

2000 ◽  
Author(s):  
Peter D. Mule ◽  
Michael D. Hill ◽  
Henry P. Sampler
1997 ◽  
Vol 119 (1) ◽  
pp. 20-27
Author(s):  
R. G. Longoria ◽  
V. A. Narayanan

This paper presents the modeling and analysis of a novel vibration suppression device. This reflector system exerts inertial forces, induced by tuned pendular motion, to control translational vibration of a primary system. Tuning of the reflector critically depends on the parameters of the pendula and on the rotational speed at which they are spun about an axis oriented parallel to the undesired motion. Consequently, one of its most appealing attributes is this devices’s ability to be tuned to, and thus actively track, the dominant frequency of disturbance forces. The paper describes how governing equations from an integrated physical model are developed using a bond graph approach and then used to derive relations applicable in design of an inertial reflector system. It is shown how the model supports component selection and tradeoff studies as well as simulation. Experimental results from testing of a laboratory realization of a prototype system are used to verify the design and to compare with simulation of a mathematical model. The results from the laboratory demonstrate the ability of the inertial reflector to control steady and transient vibration, and the favorable results suggest extended investigation for active vibration control situations. In particular, applications in low frequency vibration mitigation are promising.


2019 ◽  
Vol 430 ◽  
pp. 311-317 ◽  
Author(s):  
Guoqing Chen ◽  
Bin Xue ◽  
Jianfeng Yang ◽  
Yiyi Zhao ◽  
Xingfeng Wang ◽  
...  

Solar Energy ◽  
2018 ◽  
Vol 167 ◽  
pp. 220-230 ◽  
Author(s):  
Evangelos Bellos ◽  
Emmanouil Mathioulakis ◽  
Elias Papanicolaou ◽  
Vassilis Belessiotis

2021 ◽  
Vol 36 (1) ◽  
pp. 35-43
Author(s):  
M. Längauer ◽  
G. Zitzenbacher ◽  
C. Burgstaller ◽  
C. Hochenauer

Abstract Thermoforming of thermoplastic composites attracts increasing attention in the community due to the mechanical performance of these materials and their recyclability. Yet there are still difficulties concerning the uniformity of the heating and overheating of parts prior to forming. The need for higher energy efficiencies opens new opportunities for research in this field. This is why this study presents a novel experimental method to classify the efficiency of infrared heaters in combination with different thermoplastic composite materials. In order to evaluate this, different organic sheets are heated in a laboratory scale heating station until a steady state condition is reached. This station mimics the heating stage of an industrial composite thermoforming device and allows sheets to slide on top of the pre-heated radiator at a known distance. By applying thermodynamic balances, the efficiency of chosen parameters and setups is tested. The tests show that long heating times are required and the efficiency of the heating is low. Furthermore, the efficiency is strongly dependent on the distance of the heater to the sheet, the heater temperature and also the number of heating elements. Yet, using a full reflector system proves to have a huge effect and the heating time can be decreased by almost 50%.


2015 ◽  
Vol 23 (1) ◽  
pp. 78-82
Author(s):  
王成龙 WANG Cheng-long ◽  
马军 MA Jun ◽  
范多旺 FAN Duo-wang

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