Related Experiment Video
Updated: Jul 8, 2026
09:41
Blast Quantification Using Hopkinson Pressure Bars
Published on: July 5, 2016
Pressure measurements in laboratory-scale blast wave flow fields.
S Rahman1, E Timofeev, H Kleine
1Department of Mechanical Engineering, McGill University, 817 Sherbrooke St. West, Montreal, Quebec H3A2K6, Canada.
The Review of Scientific Instruments
|January 1, 2008
Summary
Finite size and response time of pressure transducers can significantly underestimate blast wave intensity, especially with side-on setups. Use pressure measurements from small charge experiments with caution.
Area of Science:
- Fluid Dynamics
- Shock Wave Phenomena
- Measurement Science
Background:
- Blast wave flow fields from small explosive charges (milligram silver azide) present challenges for accurate pressure measurement.
- The finite size and response time of pressure transducers can cause temporal and spatial averaging, distorting critical blast wave parameters.
Purpose of the Study:
- To investigate the impact of transducer averaging effects on pressure measurements in blast wave flow fields.
- To compare face-on and side-on pressure transducer setups and their susceptibility to averaging errors.
- To validate numerical simulations of transducer averaging against experimental data.
Main Methods:
- Simultaneous experimental measurements using face-on and side-on pressure transducers with time-resolved optical flow visualization.
- Numerical modeling using an Euler flow solver to generate blast flow fields.
- Development of a numerical pressure transducer model to simulate averaging effects.
Main Results:
- Experimental and numerical data indicate significant underestimation of blast wave intensities due to pressure signal averaging.
- The side-on pressure transducer setup is particularly vulnerable to averaging errors.
- Face-on setups yield accurate results only when the transducer is sufficiently distant from the explosive charge.
Conclusions:
- Pressure measurements in experiments involving small charges require careful interpretation due to transducer averaging effects.
- Effective averaging can lead to a substantial underestimation of blast wave intensity, particularly with side-on configurations.
- Optimizing transducer placement and considering averaging effects are crucial for reliable blast wave characterization.
Related Concept Videos
01:28Pipe Flowrate Measurement
In pipe flow measurement, orifice, nozzle, and Venturi meters are commonly used to determine fluid flowrates by constricting the flow area, which increases fluid velocity and reduces pressure. This pressure difference, governed by Bernoulli's principle and adjusted for real-world conditions, is essential for calculating flowrate. Each meter type is suited to specific applications based on accuracy, efficiency, and compatibility with various flow conditions.
The orifice meter is a simple,...
The orifice meter is a simple,...
01:28Pipe Flowrate Measurement: Problem Solving
A spray tank system is engineered to uniformly distribute a pest-control liquid across plants by using a pressurized mechanism. The tank, pressurized to 150 kPa, holds the pesticide at a height of 0.80 meters. Liquid flows from the tank through a 1.9 meter pipe with a diameter of 0.015 meters, angled at 0.698 radians, ultimately reaching a 0.007 meter nozzle that sprays the pesticide. Accurate calculation of the system's flow rate is crucial to ensure uniform application, and this is achieved...
01:16Measurement of Fluid Pressure
Fluid pressure is commonly measured using devices called manometers, which rely on liquid columns to indicate pressure differences. The height of a liquid column in a manometer reflects the pressure exerted by the fluid, providing a simple yet effective means of measurement. Different types of manometers serve specific purposes based on their configurations and the type of fluids involved.
A basic form of manometer is the piezometer, a vertical tube open at the top and filled with the same...
A basic form of manometer is the piezometer, a vertical tube open at the top and filled with the same...
01:14Fluid Pressure
In mechanical engineering, fluid pressure plays a critical role in designing systems that utilize liquid flow, such as hydraulic systems, pumps, and valves. When designing these systems, engineers must ensure they can withstand the forces created by fluid pressure to avoid damage or failure.
According to Pascal's law, a fluid at rest will generate equal pressure in all directions. This pressure is measured as a force per unit area, and its magnitude depends on the fluid's specific weight or...
According to Pascal's law, a fluid at rest will generate equal pressure in all directions. This pressure is measured as a force per unit area, and its magnitude depends on the fluid's specific weight or...
01:24Static, Stagnation, Dynamic and Total Pressure
The concept of static, stagnation, dynamic, and total pressure is fundamental in fluid dynamics, often explained using Bernoulli's equation: