Stream change learn fundamental concept

Shed denaturation to differentiate simply to be mixed for stretch, stickiness normally plasticity, plasticity can regard the combination that is flexibility and stickiness in formally.

(1) solid of flexibility of ideal of good solid body is obedient tiger model is mensurable, call a tiger to overcome solid again so.

In type, σ and ι are stress; ε and γ are meet an emergency; E and G are measured for stretch model respectively and cut modular amount; D and J part to be mixed for flexibility soft volume cut soft amount, modular quantity and soft volume each other are reciprocal.

To the circumstance of a kind of extreme, e= ∞ , no matter bring to bear on,how old force object also won't happen be out of shape, namely, this kind of object is called solid body of a few lis of mind of good rigid body or Europe.

(2) Newton of obedience of fluid of ideal fluid ideal is mensurable, call Newtonian fluid again so, fluid obedience concerns simply as follows

In type, η is viscosity, namely viscosity definition is cut stress, compare with what cut rate γ , when η = is invariable, this kind of fluid calls Newtonian fluid. The viscosity of Newtonian fluid is not followed cut shear stress to be changed with the change that cuts rate, small element liquid belongs to this kind.

The layer flows when viscosity token fluid flows between inside the size of attrition force, this kind inside attrition force is by fluid interior mutual appeal and element are irregular between the element move and cause. System of one laminar flow should move ahead, the appeal between the element that is about to overcome body of this laminar flow and layer of its photograph adjacent and the motivation that the element moves, it is certain to should be overcome namely inside attrition force. The viscosity of the fluid is bigger, explain the attraction between the element is bigger, when flow inside attrition power is greater also, consequently flow rises to also jump over difficulty, that is to say, when small element liquid flows, velocity of flow is larger, the resistance that get is greater also.

(3) the fluid that non Newton fluid always does not accord with Newtonian fluid formula, a general designation is non Newton fluid, its midstream changes behavior has with what time has nothing to do: False plasticity fluid, bilge plasticity fluid and Bin Han (Bingham) fluid, curve of their going from place to place is like graph 6-1 (A) with graph 6-1 (B) be shown.