Proportional Valve simulation

Aim:

To perform the simulation of proportional valve for diffrent lifts keeping other parameters constant .

Theory:

All pressurized systems require safety devices in order to protect people, processes and properties. As soonas mankind was able to boil water to create steam, the necessity of the safety device became evident. Earlyin the 19th century, boiler explosions on ships and locomotives frequently resulted from non-working safetydevices, which led to the development of the first safety relief valves. In order to prevent overpressure in a system the safety relief valve is an important type of device. The safety relief valve operates by releasing a volume of fluid from within the system when a predetermined maximum pressure is reached, there by reducing the excess pressure in a safe way.

In order to determine which how much force we need to open the valve we carry out this simulation .Determining the force applied by the fluid on the fixed wall will help us in designing of spring to be used to hold the spindle .So bascially when this preset amount of force is reached the spindle will open releasing all the excess pressure .

Geometry:

Following boundaries were assigned in software:

Case setup:

Gas simulation with participating fluid as air.

Density based solver selected .

Following time parameters were selected

Boundary condition :

Pressure inlet of 3000000pa

Pressure outlet of 101325pa

Spindle ,Inlet wall and outlet wall assigned as wall boundary

Meshing:

Case 1 (Without adaptive mesh refinement)

Base mesh set as 0.004

Case 2 (With adaptive mesh refinement)

Base mesh selected as 0.005 & velocity amr of scale 1 & sgs parameter of 0.1(10%) provided

Plots:

Massflowrate:

For 3 mm lift we observe massflow rate with and without amr at outlet .We can conclude that our adaptive mesh refinement worked as we got an value of around 4.2kg/s

A deviation of 0.4kg/s was observed between the two diffrent mesh size

For 4 mm lift we observe massflow rate with and without amr at outlet .We can conclude that our adaptive mesh refinement worked as we got an value of around 4.6kg/s

deviation of 0.4kg/s was observed between the two diffrent mesh size

For 5mm lift we observe massflow rate with and without amr at outlet .We cana conclude that our adaptive mesh refinement worked as we got an value of around 5.8

deviation of 0.4kg/s was observed between the two diffrent mesh size

Contours:

Velocity:

With the increase in lift the velocity was also observed to increase

Outlet velocity can be observed increasing with lift in plot.

Pressure :

As can be seen from the plot and animation pressure at outlet increases with increase in lift .

Pressur on spindle:

As can be observed from the animation due to the shape of spindle the pressure force on the spindle increases with increase in lift .

Theory behind it:

A larger area of the spindle is exposed to the fluid in open position than in closed position,
which results in a larger hydraulic force from beneath,

conclusion:

The simulation of the proportional valve ran successfully and results were analysed .