Developing the Competitive Edge
.308 Caliber 155 grain Sierra BTHP: A Case Study
Project Overview
BMI did a case study on the 155 grain .308 caliber Sierra boat-tail hollow point bullet to prove the accuracy of their CFD prediction for external ballistics of a projectile. The .308 Sierra was chosen because it is the most popular Plama competition bullet. For this reason there is also a great deal of experimental data available for the drag and flight characteristics.
BMI performed aero analysis and advanced geometry modeling of the bullet using codes developed by NASA. The solution was then compared to existing data to confirm accuracy.
Additional Project Details
BMI performed a full Viscous Navier Stokes analysis:
- @1,000,000+ grid points required
- Analysis included the simulated spin of the bullet
- 15 minutes to converge using a computing cluster
- Detailed analysis of results by experienced engineer required
Project Results
BMI's drag prediction results fell right in the middle of existing data for the bullet. The results were EXTREMELY ACCURATE!
Project Images
At A Glance
Project Goal
Use computational fluid dynamics to prove the accuracy of BMI's tools for drag predication of a ballistics projectile.
The Techniques
- High Density Surface and Volume grid
- Simulated spin included in analysis
- Flow Visualization
- Navier Stokes Analysis
The Results
Extremely Accurate!