Non-Newtonian Fluid
Definition
A fluid whose viscosity changes with the shear rate. Blood thins under fast shear (a fast swing of a weapon) and thickens at rest, which is why cast-off stains have a characteristic tear shape.
Related terms
- Area of Convergence
- The 2-D point on a surface where the projected trajectories of multiple impact stains intersect. It's the floor-projection of the impact source.
- Area of Origin
- The 3-D point in space where the blood-shedding event occurred, derived from the area of convergence plus the angle of impact for...
- Cast-Off
- Blood thrown off a swung object (a hammer, a knife, a bat). The trail records the arc of the swing and often...
- Parent Stain
- The primary drop that produces a drip pattern. The smaller surrounding spatters are the satellite spatter; together they tell you about drop...
- Surface Tension
- The cohesive force at a liquid's surface that lets a drop hold a spherical shape in flight. Whole blood sits around 58...
Explained in
- Bloodstain Pattern Analysis: Passive, Transfer and Impact PatternsA fluid whose viscosity changes with the shear rate. Blood thins under fast shear (a fast swing of a weapon) and thickens at rest, which is why cast-off stains...