Engineering & Testing

Pushing the boundaries of engineering desing and manufacturing

Computational Fluid Dynamics Modelling

The shape of the arrowhead blades is similar to the aerofoil shape of an aircraft wing. The movement of air over this shape produces a pressure differential between the two sides of the blade. This pressure differential generates a rotational movement along the axis of the arrow as it moves through the air. This rotational movement of the arrow is similar to gyroscopic motion and provides enhanced directional stability and accuracy as it moves towards the target.

Surface Friction

3D flow pattern shows the air path taken over the broadhead. Green colour is showing attached flow which is following the curvature geometry of the broadhead. The blue shows the flow separation and the red shows higher friction.

Vertical Streamlines

The vertical streamlines showing the air flow being pushed over the Wing-Blade increases speed and therefore creating a suction effect.

Wind Noise

The wind noise generated around the broadhead is a result of turbulent kinetic energy being translated into sound energy. This is calculated using the Lighthill theory, and therefore, it is an indicative analysis. Nevertheless, the results are ‘whisper quiet.

Surface Pressure

As per the “Bernoulli Equalization” which states that the pressure goes down if the air speed increases. Centipoise (CPS) is the viscosity value that is assigned to liquids. It is a unit of dynamic viscosity. A fluid with a low centipoise will flow and move easily and fast. A rating of a higher centipoise is going to flow much slower.

Horizontal Streamlines

The streamline and arrow show the spin created as it flows along the shaft axis.

Horizontal Streamline Section

A cross-section through the horizontal streamline and the arrow shows the spin created as it flows along the shaft axis.

Streamline Isometric

Surface Friction Section

A surface friction cross-section taken through the 3 Blade Broadhead.

Nomad Broadhead Metallurgy

Nomad broadheads are manufactured using a proprietary process to achieve optimum steel metallurgy. Our blades have been independently tested by a NATA certified laboratory for blade hardness. The testing showed great results, achieving on average over 62 HRC.

Upon further testing at we aim to have our broadheads hardened to a minimum 56-58 Rockwell C Hardness (HRC). We found that keeping the hardness slightly below 60 HRC is optimum for higher impact stress while holding edge retention.

We had made allowance for cold weather stress increase. Typically the hardness level of steel will increase in sub temperatures, thus increasing its HRC (typically 1-2 points).

Fig 1: Macroscopic view of broadhead cross-section showing location of hardness testing.

Fig 2 & 3: Magnifications as per scale bars included. Various micro-graphs showing the core structure of the broadhead after polishing and etching to reveal the hardened steel grain boundaries and underlying phase micro-structure. The higher magnification image provided in Fig 3. shows spheroidised carbides in a ferrous matrix consistent with the quench and tempered hardening heat treatment used as part of the proprietary arrow head manufacturing process. The spheroidised carbides enhance the impact toughness of the blade whilst providing high hardness.

High blade hardness is important to provide superior edge sharpness, whilst good impact toughness is important to minimise blade cutting edge fractures on impact. The excellent “through” hardness of the Nomad broadheads means you can continue to re-sharpen these blades and maintain the same constant cutting edge performance.

Fig 1.

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Fig 3.