A Novel, High Range-to-Resolution Ratio, Optical Sensing Technique for High Speed Surface Geometry Measurements

1987 ◽  
Author(s):  
Robert D. Lorenz
Keyword(s):  
High Speed ◽  
Optical Sensing ◽  
Surface Geometry ◽  
High Range

Introduction of new surface geometry to join Ti-6Al-4V and SS304L by friction welding

2020 ◽  
Vol 16 (5) ◽  
pp. 1233-1244
Author(s):  
M. Balasubramanian ◽  
R. Kumar
Keyword(s):  
Friction Welding ◽  
High Speed ◽  
Joint Strength ◽  
Ti Alloy ◽  
Surface Geometry ◽  
Dissimilar Joints ◽  
Content Type ◽  
Welding Machine ◽  
More Care ◽  
Copper Coin

PurposeIn friction welding of dissimilar joint method, few material compositions are not possible to weld effectively. For better dissimilar metal joining in friction welding, the interlayer techniques are used by the third metal to increase the diffusion for suitable metal bonding. The interlayer metals are popularly held by coating, foils, sheet and solid rod form. The coating method needs more care for surface preparation with special coating equipment with high workmanship. In case of foil as intermediate metal, more care is neededfor holding between the metal; most of the time this technique has the possibility of failure by peeling off from the contact surface during high speed rotation with pressure during friction generation.Design/methodology/approachIn this investigation, a copper coin was machined to a suitable size (transition fit) to suit the recess inside the SS rod. The mating surfaces of Cu coin, SS rod and Ti alloy were machined, polished to mirror finish and handled in friction welding machine. The purpose of the transition fit between the coin and SS rod is for holding the same intact before the beginning of the process.FindingsSuccessful joint was achieved with good joint strength at less time. Empirical models were established to fin out the joint strength at any given parameter within the range of investigationResearch limitations/implicationsThe models developed can be used only within the range of investigation considered for experimentation.Practical implicationsThe paper includes implications for the development of a method of joining any dissimilar jointsOriginality/valueIn this investigation, a copper coin was machined to a suitable size (transition fit) to suit the recess inside the SS rod. The mating surfaces of Cu coin, SS rod and Ti alloy were machined, polished to mirror finish and handled in friction welding machine. The purpose of the transition fit between the coin and SS rod is for holding the same intact before the beginning of the process.

Studies of two-dimensional liquid-wedge impact and their relevance to liquid-drop impact problems

1985 ◽  
Vol 401 (1821) ◽  
pp. 225-249 ◽  
Keyword(s):  
High Speed ◽  
Liquid Drop ◽  
Time History ◽  
Drop Impact ◽  
High Speed Photography ◽  
Two Dimensional ◽  
Surface Geometry ◽  
Repeated Impact ◽  
Liquid Impact ◽  
The Impact

In the initial stage of liquid-drop impact, the contact region expands faster than the wave speed in the liquid. This causes compressible behaviour in the liquid, and high transient pressures. High-velocity jetting results when the wave motion in the liquid overtakes the expanding contact edge and moves up the free surface of the drop. The detailed pressure fields in this early time history of impact have been calculated by Lesser ( Proc . R . Soc . Lond . 377, 289 (1981)) for both two and three-dimensional liquid masses and for targets of finite admittance. An important result is that the edge pressures exceed the central ‘water-hammer’ pressure 3ρ 0 CU i and at the time of shock-detachment approach ca . 3ρ 0 CU i . At this stage the edge pressures, for both spherical drops and two-dimensional liquid wedges, depend only on the impact velocity and the instantaneous angle between the liquid and solid surfaces. This suggests that the essential features of the early stage of liquid impact can be usefully studied by producing impacts with two-dimensional liquid wedges, and predicted data for pressures, shock angles and velocities are presented. Experiments are described for producing impacts with preformed shapes by using water-gelatine mixtures and observing the impact events with high-speed photography. The results confirm the main features of the model and give information on edge pressures, jetting, cavitation in the liquid and the effect of the admittance of the solid. The relevance of the results to the damage and erosion of materials subjected to liquid impact is discussed. In particular, it is possible to explain the apparently low damage-threshold of some materials, the form of damage and its development with repeated impact. The study highlights the importance of the detailed surface geometry in the region of contact.

Optical sensing of sound fields: Non-contact, quantitative, and single-shot imaging of sound using high-speed polarization camera

2016 ◽  
Vol 140 (4) ◽  
pp. 3087-3087
Author(s):  
Kenji Ishikawa ◽  
Kohei Yatabe ◽  
Yusuke Ikeda ◽  
Yasuhiro Oikawa ◽  
Takashi Onuma ◽  
...  
Keyword(s):  
High Speed ◽  
Optical Sensing ◽  
Single Shot ◽  
Sound Fields ◽  
Polarization Camera

scholarly journals Survivable Deployments of Optical Sensor Networks against Multiple Failures and Disasters: A Survey

Sensors ◽  
2019 ◽  
Vol 19 (21) ◽  
pp. 4790 ◽  
Author(s):  
Yongjun Zhang ◽  
Jingjie Xin
Keyword(s):  
Sensor Networks ◽  
Optical Communication ◽  
Optical Sensor ◽  
Data Transmission ◽  
High Speed ◽  
Optical Sensing ◽  
Self Healing ◽  
Multiple Failures ◽  
Sensing Data ◽  
Potential Development

Optical sensing that integrates communication and sensing functions is playing a more and more important role in both military and civil applications. Incorporating optical sensing and optical communication, optical sensor networks (OSNs) that undertake the task of high-speed and large-capacity applications and sensing data transmissions have become an important communication infrastructure. However, multiple failures and disasters in OSNs can cause serious sensing provisioning problems. To ensure uninterrupted sensing data transmission, survivability has always been an important research emphasis. This paper focuses on the survivable deployment of OSNs against multiple failures and disasters. We first review and evaluate the existing survivability technologies developed for or applied to OSNs, such as fiber bus protection, self-healing architecture, and 1 + 1 protection. We then elaborate on the disaster-resilient survivability requirement of OSNs. Moreover, we propose a new k-node (edge) sensing connectivity concept, which ensures the connectivity between sensing data and users. Based on k-node (edge) sensing connectivity, the disaster-resilient survivability technologies are developed. The key technologies necessary to implement k-node (edge) sensing connectivity are also elaborated. Recently, artificial intelligence (AI) has developed rapidly. It can be used to improve the survivability of OSNs. This paper details potential development directions of survivability technologies of optical sensing in OSNs employing AI.

A New Compensation Method of HRRP for Ballistic Targets

2013 ◽  
Vol 756-759 ◽  
pp. 3860-3864
Author(s):  
Xing Xing Li ◽  
Han Ying Yao ◽  
Wen Feng Sun
Keyword(s):  
High Speed ◽  
Computational Cost ◽  
Compensation Method ◽  
Least Square ◽  
Extraction Technology ◽  
Least Square Estimation ◽  
Range Resolution ◽  
Wideband Radar ◽  
Low Computational Cost ◽  
High Range

The influence on the high range resolution profile (HRRP) of the ballistic target caused by high speed motion is analyzed based on the wideband radar de-chirping echo. According to the characters of ballistic target echo ambiguity diagram (AD), the auto-terms line of echo ambiguity function is extracted from the corresponding binary image by skeleton extraction technology. Therefore, the problem of chirp rate estimation is transformed into the least square (LS) estimation problem. Furthermore, a new motion compensation method of HRRP for ballistic targets is proposed based on the ambiguity diagram and least square estimation theory. Simulation results show that the method can eliminate the influence of the high speed motion effectively, and it has a high estimate accuracy and low computational cost.

Laser Ranging Controlling System Based on Virtual Instrument

2014 ◽  
Vol 610 ◽  
pp. 229-232
Author(s):  
Qiong Ying Lv ◽  
Dan Dan Zhang ◽  
Ya Zhou Quan
Keyword(s):  
Data Collection ◽  
Virtual Instrument ◽  
High Speed ◽  
Laser Ranging ◽  
Programming Environment ◽  
Controlling System ◽  
Wide Range ◽  
Frequency Laser ◽  
And Storage ◽  
High Range

It has a wide range of applications in the field of domestic, meanwhile Laser Ranging has great competitive power comparing with microwave and other medium for distance measurement. At the same time, high range of frequency, data collection and processing pressure are then increased. In this paper, it puts forward a kind of Laser Ranging Controlling System based on Virtual Instrument. Using self-controlling infrared high repetition frequency laser as sending and receiving unit of the system to improve the accurate collimation and anti-noise capacity, march the alternate orientation gate .Taking usage of FPGA board as the core cell to handle large amounts of data collection in high speed. Choosing Labview Programming environment to proceed signal feature extraction, gating and storage efficiently.

scholarly journals Demonstration of a high speed hybrid electrical and optical sensing system for next generation launcher applications

2017 ◽  
Author(s):  
Selwan K. Ibrahim ◽  
Peter O’Connor ◽  
Milos Melicher ◽  
Danny Gleeson ◽  
John A. O’Dowd ◽  
...  
Keyword(s):  
High Speed ◽  
Optical Sensing ◽  
Next Generation ◽  
Sensing System

First Field Trial of Distributed Fiber Optical Sensing and High-Speed Communication Over an Operational Telecom Network

2020 ◽  
Vol 38 (1) ◽  
pp. 75-81
Author(s):  
Ming-Fang Huang ◽  
Philip Ji ◽  
Ting Wang ◽  
Yoshiaki Aono ◽  
Milad Salemi ◽  
...  
Keyword(s):  
Field Trial ◽  
High Speed ◽  
Optical Sensing ◽  
Fiber Optical ◽  
Telecom Network

Sub-Atmospheric Pressure, Subcooled, Flow Boiling of Water on Screen Laminate Enhanced Surfaces

2010 ◽  
Author(s):  
S. J. Penley ◽  
R. A. Wirtz
Keyword(s):  
Heat Flux ◽  
Reynolds Number ◽  
Surface Area ◽  
High Speed ◽  
Flow Boiling ◽  
Fold Increase ◽  
Surface Geometry ◽  
Subcooled Flow Boiling ◽  
Subcooled Flow ◽  
Flow Intensity

Subcooled flow boiling experiments with water at 0.2atm pressure assess the utility of fine filament screen-laminate enhanced surfaces as high performance boiling surfaces. Experiments are conducted on vertically oriented, multi-layer copper laminates in distilled water. The channel Reynolds number is varied from 2,000 to 20,000; and, subcooling ranges from 2K to 35K. Boiling performance is documented for ten different surfaces having pore hydraulic diameters ranging from 39μm to 105μm, and surface area enhancement ratios ranging from 5 to 37. Heat flux of up to 453W/cm2 is achieved at 35K subcooling at a channel Reynolds number of 6,000, which represents a 3.5-fold increase in Critical Heat Flux (CHF) over that of saturated pool boiling on the same surface. Results show that CHF is strongly correlated with subcooling; and the effect of subcooling is more pronounced as flow intensity is increased. It is found that CHF enhancement due to subcooling and flow intensity is intrinsically linked to the surface area enhancement ratio, which has an optimum that depends on the degree of subcooling. High speed video imagery (1200fps) and long range microscopy are use to document bubble dynamics. Boiling mechanisms inherent to subcooling, enhanced surface geometry, and CHF are discussed.

Sign in / Sign up

Export Citation Format

Share Document