10.12 and 10.13 it can be obtained that, due to high liquid velocity of turbulent flow, temperature rise is concentrated at the throttle orifice, viscous control force decreases and inertia force plays a leading role. 10.12–10.14 show flow temperature distribution in the valve chamber at initial temperatures of 50☌, 150☌ and -40☌, respectively. Laminar flow is simulated by Laminar model, and energy conversion and loss in flow process are taken into account, fluid flow mass conservation equation, momentum conservation N-S equation and energy conservation equation are used to solve the fluid problems.įigs. 5.Īt different temperatures, according to Reynolds number calculation results of flow and model, at low temperature -40☌ is laminar, and is turbulence at 50☌ and 150☌. It is assumed that wall temperature is consistent with ambient temperature. The wall boundary is solved by the method of no slip boundary and wall function conditions. The finite volume numerical method SIMPLE (semi-implicit method for pressure linked equations) is used to solve the discrete equations. The fluid is incompressible and a constant Newton fluid when flow velocity changes, its viscosity does not change. They claim a 5 year shelf life so it does not last forever.Parameters of YH-12 aviation hydraulic oil The mobil DTE 24 looks good but it is expensive and Grainger no longer sells it in qts. That is ISO 32 with anti wear additives and anti foam and anti rust. Hiball, the GJ resident jack expert says he uses AW32. viscosity for their other brands, like Omega. Shin Fu, that makes the HW jacks does not even spec that oil or spec. In fact I have even found ISO 15 hydraulic oil at Grainger and Hein Werner lists theirs at ISO 10. When you have a jack with no oil viscosity specified, like most of them what do you do? Does it even matter. I have several cans of "out of date".Mobil DTE 24 is ISO 32. Aircraft turbine oil is another source and it has "expiry dates" (lol).
beg a quart for Xmas fund contribution from a big equipment repair place. They will be deliverer to your local store or your home.
My opinion - buy a quart of what you want online. My compressor uses 4 different grades from 5W to 30W depending on operating temperatures. There is no "one size fits all" but someone markets it as such and consumers lap it up from Auto and Box stores. "Jack oil" without an ISO rating is a bit like buying "compressor oil", "pressure washer oil" "2-stroke oil" and what not.
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