Diaphragmless shock wave generators for industrial applications of shock waves

Hariharan, M.; Janardhanraj, S.; Saravanan, S.; Jagadeesh, G.

doi:10.1007/s00193-010-0296-5

Cited by 24 publications

(11 citation statements)

References 9 publications

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“…This holds true even for other devices that are used to generate shock waves for biological applications, like lithotripters. Therefore, for the in vivo studies we have used a diaphragmless shock tube (DST) which generates low energy shock waves and the area of impact is larger so as to expose the entire body of the mouse to shock waves 27 . A conventional shock tube is a simple device having two sections, a driver section and driven section, separated by a metal diaphragm.…”

Section: Resultsmentioning

confidence: 99%

Successful treatment of biofilm infections using shock waves combined with antibiotic therapy

Gnanadhas

Elango

Janardhanraj

et al. 2015

Sci Rep

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Many bacteria secrete a highly hydrated framework of extracellular polymer matrix on suitable substrates and embed within the matrix to form a biofilm. Bacterial biofilms are observed on many medical devices, endocarditis, periodontitis and lung infections in cystic fibrosis patients. Bacteria in biofilm are protected from antibiotics and >1,000 times of the minimum inhibitory concentration may be required to treat biofilm infections. Here, we demonstrated that shock waves could be used to remove Salmonella, Pseudomonas and Staphylococcus biofilms in urinary catheters. The studies were extended to a Pseudomonas chronic pneumonia lung infection and Staphylococcus skin suture infection model in mice. The biofilm infections in mice, treated with shock waves became susceptible to antibiotics, unlike untreated biofilms. Mice exposed to shock waves responded to ciprofloxacin treatment, while ciprofloxacin alone was ineffective in treating the infection. These results demonstrate for the first time that, shock waves, combined with antibiotic treatment can be used to treat biofilm infection on medical devices as well as in situ infections.

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Section: Resultsmentioning

confidence: 99%

Successful treatment of biofilm infections using shock waves combined with antibiotic therapy

Gnanadhas

Elango

Janardhanraj

et al. 2015

Sci Rep

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“…To solve this problem, Cunningham [5] developed an empirical formula that describes supercritical discharges of compressible flow through orifices. We reproduce this empirical formulation in (4)- (7).…”

Section: Modeling Driver Performancementioning

confidence: 99%

“…For example, while diaphragms take typically 0.2-0.5 ms to rupture [14,18], the opening time of axial pistons could vary from 0.9 ms to around 97 ms, depending mainly on their configuration, weight, and actuating pressure. Customized pneumatic actuators can exhibit opening times within the lower range of this time interval (0.9-2.4 ms) [13,14,25], while commercial actuators tend to perform in the upper range (27-97 ms) [7]. For the same actuating mechanism, transversal gates can take six times as long to open, because their effective opening distance is larger than that of axial pistons (see reference [13], for more details).…”

Section: Introductionmentioning

confidence: 99%

“…This membrane is deflated suddenly to release the pressure from the driver chamber to the driven section, providing an opening time of the order of 0.1 ms, close to the shortest time for diaphragm rupture in conventional shock tubes. These systems have been successfully tested in millimeter-size shock tubes for medical applications [26], but since elastic membranes degrade quickly due to their duty cycle, they are not recommended for large shock tubes and/or high Mach numbers [7]. Hosseini et al [11] developed a perforated housing for the elastic membrane that prevents it from degrading due to shock tube operations, enabling this system for larger-sized shock tubes.…”

Section: Introductionmentioning

confidence: 99%

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Design of a fast diaphragmless shock tube driver

et al. 2015

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In this paper, we developed a one-dimensional compressible flow model to study the behavior of various diaphragmless drivers numerically. We determined that the diameter ratio, β d , for the discharge orifice of the back chamber controls driver actuation. Driver performance is optimized by accelerating the barrier element before breaching to minimize the opening time of the driver. Our new two-body driver outperforms various designs and exhibits opening times comparable to those of aluminum burst diaphragms. Experimental results verify the effectiveness of the new driver and show that it closely follows the pressure-Mach curve for the ideal case. Planar laser-induced fluorescence images and pressure traces confirm the consistent formation of shock waves about 41 diameters from the driver.

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“…In the diaphragmless shock tube, the opening time of the shock tube inlet is the most important factor that determines the shock tube performance. Many kinds of designs have been proposed for faster opening valves, such as a rubber valve [2], double piston valves [3], and sleeve valve [4]. We herein propose an original mechanism to achieve high-speed opening of a valve.…”

Section: Introductionmentioning

confidence: 98%