Offering Unprecedented Opportunities

The need for advanced simulation technology has been brewing for a long time. When the Desert Storm conflict erupted in 1990, the need for durable equipment that could withstand the harsh effects of an arid desert environment became overwhelmingly apparent. Military vehicles, armaments, aircraft, computers, radios – all had to function reliably in order to accomplish the mission and ensure personnel safety. Through succeeding years, while asking military personnel about their biggest challenge operating in arid environments, they consistently answered, "sand and dust. It gets everywhere!"

Equipment function in desert climates became a mandate of paramount importance for armed forces when planning for operational readiness. That mandate is even more pervasive today as military and commercial operations expand throughout the global community.

Because early equipment suppliers supporting the conflict did not have test and simulation criteria to evaluate their products, the U.S. Army drafted the Military Standard (MIL-STD-810) to establish chamber test methods that replicate, rather than imitate, environmental effects on equipment. Available technology and experience at that time could only capture data with a ±70% margin for error for the stated concentration. Consequently, equipment that passed laboratory sand and dust testing failed in the field, a situation that continues today.

Most of those testing limitations are eliminated with a technology recently introduced by Air Dynamics Industrial Systems Corporation. Reducing the ±70% margin for error to only ±5%, the Desert Wind Blowing Sand and Dust Environmental Simulator tests the effects of both elements in repeatable real time from a single chamber. Its spot-on ability to predict effects of both blowing sand and dust on equipment durability offers unprecedented implications for the military, government, and industry.

"Desert Wind is a compilation of the integration of numerous core technologies," says Daniel Lehman, president, Air Dynamics, a U.S. Air Force veteran with expertise in hybrid inertial and radar navigation systems installation and maintenance, and integration of commercial mini- and micro-computers hardware and software. "It has been developed from a clean sheet design based on 20 years' experience in air and material handling. We started from scratch to solve the problem with a goal-based concept utilizing the same scientific software as NASA and Boeing to solve complex mathematical calculations."

The need for advanced simulation technology has been brewing for a long time. Previous efforts had many shortfalls:

• No ability to deliver a proven particle concentration
• No contiguous real-time recorded data output
• No single chamber to test both blowing sand and dust
• No industrial hygiene systems to protect operators from silicadust exposure
• Maintenance problems with process components in the dirty air stream Optical lenses used to establish concentration of data would cloud over, which introduced more variables, while excessive concentrations of particles would group together, a result of the chamber design.

The advanced technology in the Desert Wind design includes provisions for environmental air pollution, industrial hygiene, advanced material handling, chamber protection, and commercially available components and subassemblies. For these and other reasons, compounded by a lack of applied technology, test results were limited to a ±70% margin for error for particle concentration.

The Desert Wind technology addresses those issues with:

• A repeatable, controlled environment reaching temperatures as high as 200°F/93°C
• NIST calibrated instruments
• Automated controls for temperature, velocity, concentration, and humidity
• Repeatable proven concentration delivery system with real-time outputs
• Data logging/reporting of all test parameters
• Integrated industrial hygiene systems for user protection
• Non-destructive sand delivery
• Process component protection from wear and fouling

These advancements lead to better results in predictive test and evaluation. Drawing on its expertise with pollution control/industrial vacuum/environmental air handling systems, the Air Dynamics technology simulates a controlled environmental condition. It can test all sides of a specimen for the effects of sand and dust blowing more than 65mph, as well as extreme temperatures and humidity. The need for this knowledge is so intense that Desert Wind systems are already in use by the Crane Naval Surface Warfare Center and Canada's Aerospace Technology Center. The U.S. Army in Redstone, AL, is next in line for a custom-built Desert Wind system.

What makes this technology so unique and more effective than other methods tried during the last 20 years? Unlike early sand and dust testing attempts that relied on low-flying helicopters with vehicle convoy following to simulate desert conditions and interpret data from hand-written checklists, Desert Wind relies on advanced computer technology, proprietary software, and patent-pending hardware. It is fully automated, thermally protected, and self-contained. Temperature, concentration, humidity, and velocity settings are user selectable and discrete. Data is captured and accurately recorded from computer outputs. Because all parameters are computer-controlled to replicate exact climatic conditions, the same test under the same conditions can be repeated, consistently, to identify failure trends and predict product reliability or mean time between failures (MTBF).

Specimens are not tested under variable conditions as in previously available chambers, hobbled by clouded optical lenses or unrealistic concentrations, uneven particle distribution or particle slugs moving in a traditional short-loop configuration. With a controlled environment and no technology limitations, the Desert Wind system provides the test and simulation community with advanced capability, constructed around an industrial platform designed for many years of repeatable, scientific level testing.
 

Making it Work
Mario Aube’ (left), technical manager for Canada’s Aerospace Technology Center, observes a test through the viewing window of the Desert Wind Blowing Sand and Dust Environmental Simulator. Demonstrating the repeatable real time test is Desert Wind product manager Aaron Lehman (right) and Air Dynamics president Daniel Lehman.Once the equipment to be tested is placed inside the chamber, climatic material is introduced via an operator protected, automated loading system. A programmable logic controller (PLC) utilizes specialized software to control such variables as particle concentration, air velocity, temperature, and humidity. Discrete and analog instruments output data captured in real time, converting to a digital format, and recording every few seconds. A mass-over-time program sequence enables plotting of test progress, second by second, to adjust variables and produce a predictable outcome.

This predictability is useful in the manufacture of numerous military and commercial items ranging from aerospace components, spacecraft, missiles, and weaponry to solar panel components, rotorcraft rotor blades, and cellular telephone equipment.

"With the removal of variables that skew test results, Desert Wind simulates a high temperature controlled sand or dust environment," Lehman explains. "The system provides an advanced simulation platform for testing manufactured components subjected to desert environments while eliminating variables."

This enhanced capability creates an opportunity to upgrade the existing U.S. Army Military Standard (MIL-STD – 810G) to produce more reliable test results while better predicting equipment field performance. Because of Desert Wind's near perfect accuracy and ability to precisely measure and control variables, these standards can be revised with tighter specifications, better enabling design of durable, functional, and longer-lasting field equipment.

Although the test focuses on the ability of specimens to withstand tough arid climates, the test chamber itself also needs protection from simulated harsh environmental effects. Experience with other systems has shown that continual abrasive motion and particle buildup can erode the test chamber. To prevent this, Desert Wind has a built-in waste removal design to protect the chamber against erosion from climate simulations.

Durability and Safety
While equipment durability is a prime consideration, operator safety is also a key concern. Metal dusts, eroded from test specimens, often are combustible and pose a serious safety risk if not removed regularly. Repeated testing can create a layered concentration of volatile dust over time. Not only does this increase the chance of explosion, it also exposes operators to toxic industrial coatings such as chromium, which will erode during testing.

Desert Wind alleviates these safety threats with a fully contained automated material loading, circulation, and waste disposal system. Removal of spent material after every test session, by a built-in industrial vacuum, reduces the risk of explosion. An automated industrial hygiene ventilation system engages to provide a safer work environment and protection from operator exposure to carcinogenic silica dust. Because the process is self-contained from start to finish, toxic materials never enter the workplace and safety risks stay to a minimum.

Each turnkey, in-plant Desert Wind unit is customizable to accommodate the equipment being tested; it can hold a full-size armored vehicle or scale down to one cubic yard, based on the requirement. Actual testing is viewable through a window into the lit chamber.

Fully assembled and calibrated at the Air Dynamics facility prior to shipping, the advanced technology in the Desert Wind design includes provisions for environmental air pollution, industrial hygiene, advanced material handling, chamber protection, and commercially available components and subassemblies. This system is considered low velocity (up to 29m/sec) for land-based equipment. A high velocity, (43,000fpm) dynamic airfoil simulator is available to test full chord, short span airfoils in a dynamic configuration.

With its proprietary design, computerized controls and data collection, industrial engineering, and built-in safety components, Desert Wind is the next generation in environmental testing.

Until now, there has not been a simulator that can provide real time recorded outputs of each critical parameter of a blowing sand or dust environment. As Aerospace Technology Center Director of Innovation & Development, Stephane Carpentier, says, "Desert Wind is the best technology we have found for testing and calibration laboratories. We will use it within the aerospace and military sectors to create a parts development and certification process."

The Aerospace Technology Center currently is undergoing the International Organization for Standardization process to receive ISO-17025 certification of Desert Wind for repeatability and predictability. This certification will offer additional advantages for industry and manufacturers of equipment such as jet engines.

Initially, Air Dynamics' patent-pending technology is intended for desert environment testing and certification of military equipment and commercial applications in the automotive, wind turbine, solar panel, and aerospace manufacturing industries. Lehman is quick to point out that this chamber is best suited for heavy-duty industrial use. Test needs for lighter applications are handled, more efficiently, by leasing time on a Desert Wind system already installed at an industrial or government facility.

To learn more about Air Dynamics' Desert Wind simulator, please visit, products.airdynamics.net/category/ environmental-test-chambers.

Air Dynamics
York, PA
airdynamics.net