数字研究低频冲击列车振荡在一个分离隔离器与流发生器喷射器的分离隔离器
Jinlong Wang1, Kaijie He1, Qingchun Zhou2
1Chengde College of Applied Technology, Chengde, P. R. China.
PloS one
|July 17, 2025
概括
这项研究以数值方式研究超音速隔离器中的冲击列车振荡. 冲击列车表现出由分离区域不稳定性驱动的低频流向振荡,并由流发生器放大.
科学领域:
- 流体动力学 流体动力学
- 航空航天工程是航空航天工程.
- 高速流动的高速度流动.
背景情况:
- 超音速隔离器中的冲击列车对于发动机的稳定性至关重要.
- 了解冲击列车动态对于防止发动机不启动至关重要.
- 低频振荡可以导致显著的性能降低.
研究的目的:
- 为了数值地研究冲击列车的低频振荡.
- 分析冲击列车行为的流场和光谱特征.
- 为了确定冲击列车振荡背后的驱动机制.
主要方法:
- 在马赫3.034的两级分离隔离器的数值模拟.
- 使用计算流体动力学 (CFD) 进行详细的流场分析.
- 对压力信号进行光谱检查,以确定振荡频率.
主要成果:
- 冲击列车表现出102赫兹的低频流向振荡.
- 振荡幅度高达隔离器入口高度的2.5倍.
- 发现了两种不同的驱动机制:分离区域的不稳定性和旋流发生器效应.
结论:
- 这项研究阐明了冲击列车复杂的振荡行为.
- 分离区域的不稳定性是主要的驱动机制.
- 子发生器和管道几何学作为二次放大因子.
相关概念视频
Damped Oscillations
6.0K
In the real world, oscillations seldom follow true simple harmonic motion. A system that continues its motion indefinitely without losing its amplitude is termed undamped. However, friction of some sort usually dampens the motion, so it fades away or needs more force to continue. For example, a guitar string stops oscillating a few seconds after being plucked. Similarly, one must continually push a swing to keep a child swinging on a playground.
Although friction and other non-conservative...
Although friction and other non-conservative...
6.0K
Shock Waves
2.2K
While deriving the Doppler formula for the observed frequency of a sound wave, it is assumed that the speed of sound in the medium is greater than the source's speed through it. When this condition is breached, a shock wave occurs.
When the source's speed approaches the speed of sound, constructive interference between successive wavefronts emitted by the source occurs immediately behind it. Initially, scientists believed that this constructive interference would result in such high...
When the source's speed approaches the speed of sound, constructive interference between successive wavefronts emitted by the source occurs immediately behind it. Initially, scientists believed that this constructive interference would result in such high...
2.2K
Forced Oscillations
6.8K
When an oscillator is forced with a periodic driving force, the motion may seem chaotic. The motions of such oscillators are known as transients. After the transients die out, the oscillator reaches a steady state, where the motion is periodic, and the displacement is determined.
6.8K
Oscillations In An LC Circuit
2.5K
An idealized LC circuit of zero resistance can oscillate without any source of emf by shifting the energy stored in the circuit between the electric and magnetic fields. In such an LC circuit, if the capacitor contains a charge q before the switch is closed, then all the energy of the circuit is initially stored in the electric field of the capacitor. This energy is given by
2.5K
Steady, Laminar Flow Between Parallel Plates
341
Understanding steady, laminar flow between parallel plates is essential for analyzing and designing flow in narrow rectangular channels, commonly found in various water conveyance and drainage systems. The Navier-Stokes equations govern fluid motion and are generally challenging to solve due to their nonlinearity. However, simplifications are possible in certain cases, like the steady laminar flow between parallel plates. For this scenario, we assume steady, incompressible, laminar flow.
341
Stress Concentrations in Circular Shafts
240
Consider the elastic torsion formula, which applies to a circular shaft with a consistent cross-section. This formula assumes that the shaft's ends are loaded with rigid plates firmly attached. However, in many cases, torques are applied to the shaft through mechanisms like flange couplings or gears, which are connected by keys inserted into keyways. This application method modifies the stress distribution near the point of torque application, causing it to deviate from the distributions...
240


