Weak infrared radiation intensity measurement based on extended Duffing oscillator

2021 ◽  
Author(s):  
yongming zhao ◽  
Jian Du ◽  
Xin Wang ◽  
Chang Liu ◽  
Zhuo Li ◽  
...  
Keyword(s):  
Radiation Intensity ◽  
Infrared Radiation ◽  
Duffing Oscillator ◽  
Intensity Measurement

Numerical evaluation of the exhaust-direction effects on plume flow and helicopter infrared radiation under hover and cruise statuses

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Zongyao Yang ◽  
Yong Shan ◽  
Jingzhou Zhang
Keyword(s):  
Radiation Intensity ◽  
Infrared Radiation ◽  
Design Methodology ◽  
Main Rotor ◽  
Content Type ◽  
Exhaust Plume ◽  
Ir Signature ◽  
Plume Flow ◽  
The Impact ◽  
Rotational Direction

Purpose This study aims to investigate the effects of exhaust direction on exhaust plume and helicopter infrared radiation in hover and cruise status. Design/methodology/approach Four exhaust modes are concerned, and the external flow field and fuselage temperature field are calculated by numerical simulation. The infrared radiation intensity distributions of the four models in hovering and cruising states are computed by the ray-tracing method. Findings Under the hover status, the exhaust plume is deflected to flow downward after it exhausts from the nozzle exit, upon the impact of the main-rotor downwash. Besides, the exhaust plume shows a “swirling” movement following the main-rotor rotational direction. The forward-flight flow helps prevent the hot exhaust plume from a collision with the helicopter fuselage generally for the cruise status. In general, the oblique-upward exhaust mode provides moderate infrared radiation intensities in all of the viewing directions, either under the hover or the cruise status. Compared with the hover status, the infrared radiation intensity distribution alters somewhat in cruise. Originality/value Illustrating the influences of exhaust direction on plume flow and helicopter infrared radiation and the differences of helicopter infrared radiation under hover and cruise statuses are identified. Finally, an appropriate exhaust mode is proposed to provide a better IR signature distribution.

scholarly journals Analysis of Infrared Radiation Intensity by Water-Mist Spraying in Ship Exhaust System

2021 ◽  
Vol 2112 (1) ◽  
pp. 012019
Author(s):  
Zhongke Sun ◽  
Zhen Wang ◽  
Zhongwei Chen ◽  
Zhihua Liu ◽  
Mo Liu ◽  
...  
Keyword(s):  
Radiation Intensity ◽  
Infrared Radiation ◽  
Exhaust System ◽  
Water Mist ◽  
Mist Cooling

Abstract The infrared radiation intensity in 3~5μm of conventional ship exhaust system are so severe [1] that can be easily captured by detector. Therefore, it’s necessary to take measure like spraying water mist to decrease temperature of exhaust system in order to decrease infrared radiation intensity. In this paper, the calculation of infrared radiation intensity of conventional ship exhaust system with water-mist spraying will be given. The results show that the average and maximum infrared radiation intensity of the exhaust system can be reduced by 90.3% and 95.7% after water mist cooling.

Study of Tunnel Water Detection through Infrared Acquisition Technology Based on 3D Trend Analysis

2013 ◽  
Vol 838-841 ◽  
pp. 1370-1380
Author(s):  
Shu Hao Zhang ◽  
Ya Wei Wang
Keyword(s):  
Trend Analysis ◽  
Radiation Field ◽  
Radiation Intensity ◽  
Infrared Radiation ◽  
Tunnel Construction ◽  
Water Detection ◽  
Visualization Software ◽  
Comparison And Analysis

The study discusses a revised method of water detection through infrared acquisition technology. In the case of Xianghe tunnel construction, the authors built 3D infrared radiation field functions through 3D trend analysis. The separately calculated radiation intensity trend values and outliers were processed by the visualization software, Voxler, and transformed into 3D distribution graphs for further comparison and analysis. The result indicates that the technique and method applied in this article successfully eliminate the random interference and realize the detection of aquifer.

scholarly journals Micro-Motion Dynamics and Shape Parameters Estimation Based on an Infrared Signature Model of Spatial Targets

Electronics ◽  
2019 ◽  
Vol 8 (7) ◽  
pp. 755 ◽  
Author(s):  
Dongya Wu ◽  
Huanzhang Lu ◽  
Bendong Zhao ◽  
Junliang Liu ◽  
Ming Zhao
Keyword(s):  
Radiation Intensity ◽  
Infrared Radiation ◽  
Estimation Method ◽  
Optimization Techniques ◽  
Parameters Estimation ◽  
Geometrical Shape ◽  
Infrared Signature ◽  
Micro Motion ◽  
Periodic Fluctuations ◽  
Motion Dynamics

Infrared imaging is widely applied in the discrimination of spatial targets. Extracting distinguishable features from the infrared signature of spatial targets is an important premise for this task. When a target in outer space experiences micro-motion, it causes periodic fluctuations in the observed infrared radiation intensity signature. Periodic fluctuations can reflect some potential factors of the received data, such as structure, dynamics, etc., and provide possible ways to analyze the signature. The purpose of this paper is to estimate the micro-motion dynamics and geometry parameters from the observed infrared radiation intensity signature. To this end, we have studied the signal model of the infrared radiation intensity signature, conducted the geometry and micro-motion models of the target, and we proposed a joint parameter estimation method based on optimization techniques. After analyzing the estimation results, we testified that the parameters of micro-motion and geometrical shape of the spatial target can be effectively estimated by our estimation method.

scholarly journals Research on the Characteristics of Infrared Radiation Spectra at Zigong Acupoint within Menstrual Cycle of Healthy Female

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Meng Qin ◽  
Si-qi Ma ◽  
Zhi-ming Huang ◽  
Xue-yong Shen ◽  
Jian-zi Wei
Keyword(s):  
Menstrual Cycle ◽  
Radiation Intensity ◽  
Infrared Radiation ◽  
Statistical Difference ◽  
Radiation Spectrum ◽  
Control Point ◽  
Control Points ◽  
Total Radiation ◽  
Healthy Female ◽  
The Right

The purpose of this study was to observe the characteristics of infrared radiation spectrum of Zigong acupoint (EX-CA1) within the menstrual cycle of healthy female. We used highly sensitive infrared radiation spectrum detection system and phase-locked amplification technology to detect and analyse the infrared radiation spectrum from 1.5μm to 18μm of 32 healthy female before, during, and after menstruation at EX-CA1 and control points. The results showed that the total radiation intensity of left EX-CA1 was significantly higher than that of left control point (P<0.05) at the whole menstrual cycle, and the difference between right EX-CA1 and right control points was statistically significant before and after menstruation (P<0.05), no statistical difference during menstruation. Previous studies found that the radiation near 15μm was correlated with glucose metabolism. The results of this study showed that there were statistical differences in 10 wavelengths between left EX-CA1 and left control point from 14μm to 18μm, and there were statistical differences in 3 wavelengths on the right side (P<0.05). The left side is more prominent than the right side. The infrared radiation intensity of EX-CA1 decreased gradually with the change of cycle rhythm within menstrual cycle, but there was no statistical difference in this trend. There was no statistical difference in total radiation intensity between the right and left side of EX-CA1. Compared with the control points, the number of different wavelengths between left EX-CA1 and left control point during menstruation was significantly larger than that between right EX-CA1 and right control point (P<0.001). The results indicated that the energy of EX-CA1 was higher than control points. There was no difference in the radiation intensity between the right and left sides of EX-CA1 but there was acupoint laterality compared with nonacupoints. There was no significant rhythmic change in infrared radiation intensity of EX-CA1 during the menstrual cycle.

scholarly journals Attenuation of Infrared Radiation When Passing Through a Water Curtain

2017 ◽  
Vol 12 (1) ◽  
pp. 1-8
Author(s):  
Dalibor Balner ◽  
Karla Barčová ◽  
Michal Dostál
Keyword(s):  
Radiation Intensity ◽  
Infrared Radiation ◽  
Radiation Source ◽  
Water Mist ◽  
Water Droplets ◽  
Spray Characteristics ◽  
Ir Radiation ◽  
Water Curtain

Abstract This article focuses on the interaction of infrared (IR) radiation with water droplets. The main objective of the article is the production of water mist in order of evaluation the reduction in intensity of IR radiation. In the experiments described in this paper, a set of five different nozzles was used with various spray characteristics. The respective nozzles were gradually located between the IR radiation source and a detector and the attenuation of IR radiation was assessed. The reduction in IR radiation intensity was determined and IR radiation transmittance was calculated for the respective tested nozzles.

Investigation on Influence Mechanism of Wall Coating on Infrared Radiation Signature of Serpentine Nozzle

2020 ◽  
Author(s):  
Jie Shi ◽  
Li Zhou ◽  
Zhanxue Wang ◽  
Jingwei Shi
Keyword(s):  
Radiation Intensity ◽  
Infrared Radiation ◽  
Infrared Detector ◽  
Exhaust System ◽  
Nozzle Wall ◽  
High Radiation ◽  
Indirect Transmission ◽  
Influence Mechanism ◽  
Radiation Transmission ◽  
Radiation Area

Abstract Stealth performance is one of the most important factors to evaluate the technical level of modern battleplane. Serpentine nozzle can block the direct radiation transmission path between the high-temperature components in exhaust system and the infrared detector, thus suppressing the infrared radiation signature. However, due to the reflection characteristics of nozzle wall, this method can also cause indirect transmission of infrared radiation through the wall reflection to form a local high radiation area. Motivated by previous researches on the application of serpentine nozzle wall coating in electromagnetic radiation suppression. Wall coating is applied to serpentine nozzle to suppress infrared radiation intensity in this paper. Aiming at the situation of turbofan engine using serpentine nozzle, the influence mechanism of coating position, area and emissivity of serpentine nozzle on infrared radiation signature is calculated and analyzed, and the scheme of wall coating which has the least coating area and can effectively suppress infrared radiation transmission is also studied. The results show that reducing wall coating emissivity will strengthen the indirect transmission of infrared radiation, then cause the increase of exhaust system infrared radiation intensity, while increasing wall coating emissivity will reduce wall coating reflectivity, and the local high radiation area caused by indirect radiation transmission can be effectively prevented. The research also found that the infrared radiation signature of exhaust system can be effected only when the emissivity adjustment of serpentine nozzle wall which can be detected directly by infrared detector. After adopting the optimized wall emissivity coating scheme, the infrared radiation intensity of serpentine nozzle for turbofan can be reduced by 51.3% on the original basis while the coating area only accounts for 25.1% of the nozzle area.

General Model for Calculating Infrared-Radiation Intensity of Aerial Target and Its Application

2019 ◽  
Vol 39 (6) ◽  
pp. 0612007 ◽  
Author(s):  
贺元兴 Yuanxing He ◽  
张浩元 Haoyuan Zhang ◽  
司文涛 Wentao Si ◽  
吴统邦 Tongbang Wu ◽  
程军练 Junlian Cheng
Keyword(s):  
Radiation Intensity ◽  
General Model ◽  
Infrared Radiation
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