The accident vehicle is always an ominous sign. Many people in the second-hand market are also very afraid of picking the accident car. However, today, Xiao Bian wants to give the name of the accident car - the hero of life protection!

I remember that often car manufacturers will do collision tests in order to let consumers understand the performance. From the above picture, we see that the two cars have crashed beyond recognition! At this time, there will always be some unclear people scrawling beside the side: if you later kill and don't buy the car, how can you hit it! I think this is how much more ignorant people will complain! It's time to give everyone knowledge of science.

First, the front bumper structure of a car can be seen from the front face to the cockpit, with deformed areas, compatible areas, and protected areas. Most consumers and even the media define the front bumper as the plastic shell of the front face. In fact, the deformation zone and the compatibility zone are used to ensure collision safety components (plastic bumper shell, front impact beam, Energy absorber boxes...) all belong to the category of front bumpers.

The first section, including the plastic housing, is designed to make it easily "damaged." It is currently in the process of "damage" that it absorbs the kinetic energy generated by accidental collisions and ensures pedestrian safety. Think of it, if you replace it with high-strength steel, and then add a little corner, the pedestrian's legs will be directly abolished.

The collision beam and the energy absorption box immediately following it are mainly used to absorb the kinetic energy in mid-speed collisions, in which the impact beam absorbs kinetic energy and also acts as guiding stress to balance the crumple and ensure the mid-speed collision process. The energy is absorbed evenly and the peak of the impact acceleration is reduced as much as possible.

The main function of the energy absorber is to absorb the impact energy. Some models with high safety factors will design the energy absorption box to have multiple absorption levels. The front section is small and the strength is low, while the back section is larger and larger, and the strength is also higher. This will enable gradual absorption of energy. Purpose to achieve better energy absorption.

Behind the energy absorbing box is the front longitudinal beam. This structure is mainly used to absorb and transmit the strong kinetic energy generated by high-speed collision. This is the protagonist of the passive safety performance of the car, and also the structure that determines the life and death of the owner, and the anti-collision beam mentioned above. Or the difference between a shock absorber and a shock absorber.

In serious traffic accidents, the front longitudinal beams absorb 60% of the total collision energy through collisional deformation and bending deformation, and another part is also transmitted through the longitudinal beams to the frame structure. As for the impact beam and energy absorption The box has changed beyond recognition. In addition, the stringer design idea will require it to deform along the axis as much as possible to achieve the best energy absorption effect, which is one of the most important reference standards for analyzing the safety performance of automobiles.

The cockpit is behind the compatible zone. When the front sidemember extends to this position, it will bend down significantly. This will not only have the highest strength, but will also be provided with stiffeners to control the amount of deformation. This is the last line of defense to protect the owner's safety. The maximum level of energy absorption, and to ensure that no excessive deformation, to prevent the safety structure broke into the cockpit, was not killed, the case of being inserted in traffic accidents are not few.

Many people saw that the test car or accident car that had been hit by an unrecognizable car would say that the safety factor of the car was not good. This made it clear that the final decision was extremely rigorous. In fact, it is these damaged structures that absorb the kinetic energy of collisions in traffic accidents and protect the owners and pedestrians from the impact of powerful kinetic energy. They are reluctant to damage, and the damage must be human!

A reaction turbine is a type of Steam Turbine that works on the principle that the rotor spins, as the name suggests, from a reaction force rather than an impact or impulse force.

In a reaction turbine there are no nozzles to direct the steam like in the impulse turbine.

The fixed blades, which are the same shape as the moving blades, are mounted to the outer casing where the rotor revolves and are set to guide the steam into the moving blades.  Below is a simple diagram of reaction turbine blades:

Reaction Turbine Principle:

In the case of reaction turbine, the moving blades of a turbine are shaped in such a way that the steam expands and drops in pressure as it passes through them. As a result of pressure decrease in the moving blade, a reaction force will be produced. This force will make the blades to rotate.

Reaction Turbine Working:

A reaction turbine has rows of fixed blades alternating with rows of moving blades. The steam expands first in the stationary or fixed blades where it gains some velocity as it drops in pressure. Then enters the moving blades where its direction of flow is changed thus producing an impulse force on the moving blades. In addition, however, the steam upon passing through the moving blades, again expands and further drops in pressure giving a reaction force to the blades.

This sequence is repeated as the steam passes through additional rows of fixed and moving blades.

Note that the steam pressure drops across both the fixed and the moving blades while the absolute velocity rises in the fixed blades and drops in the moving blades.

The distinguishing feature of the reaction turbine is the fact that the pressure does drop across the moving blades. In other words, there is a pressure difference between the inlet to the moving blades and the outlet from the moving blades.

Special Aspects of Reaction Turbines

• There is a difference in pressure across the moving blades. The steam will, therefore, tend to leak around the periphery of the blades instead of passing through them. Hence the blade clearances as to maintain as minimum as possible.
• Also, due to the pressure drop across the moving blades, an unbalanced thrust will be developed upon the rotor and some arrangement must be made to balance this.

Reaction Steam Turbine

Reaction Steam Turbine

Shandong Qingneng Power Co., Ltd. , https://www.steamturbine.be