Stiffness Scaling for Solid-Cloth Parachutes

Johari, Hamid; Desabrais, Kenneth J.

doi:10.2514/2.3166

Cited by 22 publications

(12 citation statements)

References 11 publications

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“…This should be noted that R m contains a threshold for each type of parachute below which t O =t f is approximately unity. This agrees with [12,23,27].…”

Section: Resultssupporting

confidence: 84%

“…Moreover, a comparison between Tables 2 and 4 shows that to theoretically halve the initial velocity (from 100 to 50 m=s) results in an approximately quarter reduction of the opening shock. This may be compared to a correlation used to calculate the opening shock as given by [6,7,10,12,[23][24][25][26][27][28][29] …”

Section: Resultsmentioning

confidence: 99%

“…Johari and Desabrais [27] used dimensional analysis to study the parameters affecting the inflation of solid cloth parachutes. Based on a comparison between sub-and full-scale flat circular C9 parachutes in water and wind tunnels, a relative stiffness index was proposed for filling and opening time correlation.…”

Section: Introductionmentioning

confidence: 99%

“…Thus, theoretical studies are motivated using experimental-based correlations to acquire force history [5][6][7][10][11][12][13][14][15][16][22][23][24][25][26][27][28][29][30][31][32]. In this direction, Berndt and Deweese [5] used parachute opening images to study filling time as well as the variation of canopy projected area.…”

Section: Introductionmentioning

confidence: 99%

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Decisive Roll of Filling Time on Classification of Parachute Types

Mohaghegh¹,

Jahannama²

2008

Journal of Aircraft

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In a low altitude recovery, a parachute has to reduce the recovery mass velocity to a predefined velocity before its ground impact within a vertical distance as low as possible. The article classifies various parachutes based on the parachute opening shock and distance necessary to satisfy the steady descent condition in an unreefed situation using numerical solutions of experimental and theoretical relations linked with the parachute opening and flight dynamics. Results show that the parachute filling time is the main parameter to differentiate all parachutes from each other. Based on the parachute filling time, slotted parachutes velocity history coverage locates between ribbon and ringsail parachutes, whereas solid textile parachutes span a range between extended skirt 14.3% and guide surface parachutes. In each group, a decrease in the parachute filling time as a result of the change in the parachute type causes an increase in the parachute opening shock as well as a decrease in the parachute steady distance.parachute drag force F max = opening shock g = gravity acceleration m = total recovery mass n = parachute filling parameter R m = mass ratio t = elapsed time t f = parachute filling time V = velocity X p = parachute shock reduction factor x = parachute filling distance = correlation coefficient = power of filling function = correlation exponent = air density Subscripts O = opening instant p = projected t = instant 0 = nominal

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“…This should be noted that R m contains a threshold for each type of parachute below which t O =t f is approximately unity. This agrees with [12,23,27].…”

Section: Resultssupporting

confidence: 84%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Decisive Roll of Filling Time on Classification of Parachute Types

Mohaghegh¹,

Jahannama²

2008

Journal of Aircraft

View full text Add to dashboard Cite

show abstract

“…As noted in the next section, the small-scale canopies used in the experiments had indices which were approximately three times that of full-scale canopies. However, canopy performance has been shown to be a weak function of the canopy stiffness especially during steady descent (Johari and Desabrais, 2003).…”

Section: Dimensionless Parametersmentioning

confidence: 99%