Traditional emitters used for downhole acoustic detection have limited radiation frequency and energy, making it difficult to transmit high-precision signals over long distances. This paper presents a plasma emitter in which high-pressure discharge generates powerful spherical impulse wave with wide range. First, the characteristics of needle-plate are analyzed using high-voltage experiments simulation models underwater emitters. Subsequently, advanced modifications made structure...

In acoustic deep detection technology, conventional monopole, dipole, and phased-array sound sources are far inferior to impulsive in frequency amplitude. But impulse mostly work under high-power, high-voltage, high-current conditions, which difficult be applied downhole. The purpose of this paper is reduce the power source system at same time stimulate excellent wave characteristics. Firstly, an experimental using needle-rod electrodes was constructed, discharge results were analysed....

The wave frequency and energy of traditional piezoelectric emission sources used in acoustic logging are limited, which results an inadequate detection resolution for measuring small-scale geological formations. Additionally, the propagation these waves formations is prone to loss noise interference, restricting only a few tens meters around well. This paper investigates impulse sound source, new source that can effectively enhance range by generating excitation through high-voltage...

Piezoelectric transducers are commonly used in acoustic well logging. However, the low frequency and narrow range of waves limit achievable detection accuracy. In addition, amplitude causes useful information to be easily masked by noise during detection, which affects accuracy geological identification makes it difficult detect formations tens meters away. This paper proposes a microporous liquid-electric transmission transducer, electrode structure generates powerful shock wave through...

The evaluation progress using the cloud model executes transform between qualitative object and ration makes get more persuasion to be easily suitable. By model, this paper maps indefinite comment as different droplets with fine variations, variation of each factor’s weight correctable mathematic expectation cloud, thus puts forward a comprehensive based on model. Simulation results show that: new also can give us set factors impersonally content distinguishes from traditional ways.

This paper studies the vehicle rollover warning based on running state parameters which are easy for collecting. By taking advantages of neural network and support vector machine, this analyzes probabilities in scenario single lane change establishes a model could predict 0.4 seconds advance particular type vehicle. According to validation experiments Ve-DYNA is dynamic simulation software, results validate models good performance with maximum error as 0.04 second no missing cases indicates...

The parameter identification is necessary for precise control orbit and attitude of Space Robot. This paper presents a method inertia properties space robot which based on the momentum conservation. As initial Robot hardly known, we have to discuss detailed in two options. first option, known assumes it zero, then can solve all unknown parameters equations; second it’s unknown, has be solved steps. step identify mass center spacecraft; tensor spacecraft. In end, build model simulation;...

To research the radiation properties of heat flow around aircrafts’ surface in hypersonic flight, a fusion algorithm to calculate aircrafts is proposed this paper. Firstly, use computational fluid dynamics (CFD) basic aerodynamic parameters which are inside boundary layer, such as pressure, density, etc. Subsequently, model built by using engineering algorithm. Then, we can build effectively. The result reflect distribution surfaces accurately, and provide data support study its optical...

LDRI system stands for Laser Dynamic Range Imager. It has been used in STS-114 mission 2005 as the main sensors to realize an on-orbit inspection of thermal protection which covers Orbiter spacecraft. The basic is phase discrimination and key technology realization optoelectronic mixing (OEM) using ICCD. Unfortunately, 2 drawbacks arise from usage ICCD, including high voltage (~2000V) PMT drivers difficulties modulations. SiPM a rather novel detector similar performances does but only...

A novel space environment effects equivalence model used for optical detection is proposed in this paper. In model, the on system are equivalent to defocus, image motion, vibration and noise. Besides, modulation transfer function of presented. The can avoid analyzing so many influence factors at same time. Moreover, provide some basis determine parameters which difficult measure. Some numerical simulations made test validity capability model.

Since spectral curves were obtained by experiment, on the basis of fully use waveform characters, a new method for matching pretreatment has been proposed in this paper. Corresponding to curve, we can accurately get absorption curve number bands, it effectively suppress effects noise according times fitting points. Besides, also prominent peak point material. This have an effective influence initial period match and detailed resolution; some numerical simulations made test validity capability method.

The investigation of the flow characteristics inside nozzle becomes more and important because status in fuel injection significantly influence emission economy diesel engines. Due to limited experimental conditions, we can make use computer simulation, UG models be used predict pattern injectors promote level selection design injectors. In this investigation, model is calculated by FLUENT software after considering compressibility viscosity fuel. By studying, distribution field nozzle,...

An optical detection system is built by using model building method based on the modulation transfer function. The effects of space environment and noise have been considered added in this system. In model, we solve establishment complex imaging problem dynamic running environment. Besides, can meet demand different target task performance stages life span parallel analysis evaluation numerical simulations are performed to check validity capability proposed KEYWORD: Space target; Dynamic...

The launch site security issues have been became the focus of world’s research for several decades. Aiming at filling system, pipe vibration caused by liquid hydrogen which flowed through bend was studied. And based on computational fluid dynamics, flow field simulated according to numerical simulation method. Then, changes parameters i.e. pressure and velocity were observed. results showed that: (1) speed would a sudden change direction it create vortex could erode lead in region. As...

With aiming at the problem of liquid hydrogen flowing through filling system in space launch site, author set up a math model laminar flow and coupled with analysis condition tube. Based on computational fluid dynamics, field was studied according to numerical simulation method. Then, changes parameters i.e. pressure velocity tube were observed. Simulation results showed that, inlet-section, there existed boundary-layer, besides, which changed continually not stable until flowed on-way. In...

Workflow technologies are becoming pervasive in the area of space. They enable execution space business processes distributed and ubiquitous computing environments. However, there some problems such as cross-platform workflow which need to be solved urgently test launch. Aiming at enhancing efficiency launch, engine model launch based on JMX was designed. And routing control algorithm proposed. At last, performance system analyzed. The applied a base successfully. actual operation tests show...

A novel near space target optical properties modeling method based on the reverse Monte Carlo tracking is proposed. Both environment characteristics in and light transmission different detection platform mode are considered analysis detail. The invalid can be eliminated adaptively this model. According to phase relationship of target-observing systems-the sun, obtained. Some numerical simulations made test accuracy capability proposed method.

With aiming at the problem of liquid hydrogen flowing through filling system in space launch site, author set up a turbulence model and coupled with analysis condition tube. Based on computational fluid dynamics, flow field was studied according to numerical simulation method. Then, changes parameters i.e. pressure velocity tube were observed. Simulation results showed that, inlet-section, there existed boundary-layer, besides, which changed continually not stable until flowed on-way. In...

According to the characteristics of information resources in modern acquisition, such as heterogeneous, distributed, loosely coupled, problems and deficiencies workflow technology products were analyzed. Dynamic service grouping strategies based on SOA was proposed proved theory. In addition, architecture built engine simulation-based acquisition (SBA) designed. Therefore, legacy code can be wrapped grouped dynamically from dynamic generic factory. Grouping strategy according SPOT satellite...