Dynamic Pressure Distribution on Parachute Canopies PDF Download

Author: C. Saliaria
Publisher:
ISBN:
Category : Parachutes
Languages : en
Pages : 8

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Book Description
The pressure distribution on the canopies of several types of parachutes shall be determined under finite mass conditions. These types are the Circular Flat, the Extended Skirt, the Ring-slot and the Circular Flat Ribbon parachute. The pressure distribution during filling and at steady state shall be related to the instantaneous canopy profile. Furthermore, an attempt shall be made to establish a general relationship between canopy profile and pressure distribution. The snatch velocity shall be held constant at approximately 110 knots, while the canopy loading (W/S) shall be limited to the range between 0.3 and 0.7 lbs/ft2.

Author: H.-D. Melzig
Publisher:
ISBN:
Category : Parachutes
Languages : en
Pages : 8

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Book Description
Four basic types of textile parachute canopies (Circular Flat, Extended Skirt, Ringslot, Circular Flat FIST) shall be investigated under finite mass conditions. The dynamic pressure distribution on the canopies during filling shall be measured and related to the canopy profile shape. The establishment of a general relationship between canopy profile shapes and pressure distribution shall be attempted. The deployment speed shall be held constant at approximately 110 knots, the canopy loading shall be limited to between 0.3 and 0.7 lbs/ft2.

Author: H.-D. Melzig
Publisher:
ISBN:
Category : Parachutes
Languages : en
Pages : 160

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Book Description
An experimental investigation was conducted to determine the differential pressure distribution on the canopies of four types of parachutes (Circular Flat, 10 % Extended Skirt, Ringslot, Circular Flat Ribbon) during the period of inflation under finite mass conditions. In flight tests the differential pressure on the cord and the gore center line was measured with four pressure transducers distributed over the canopy in equal distances from the skirt to the vent.

Author: H.-D. Melzig
Publisher:
ISBN:
Category : Parachutes
Languages : en
Pages : 14

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Book Description
The pressure distribution on the canopies of several types of parachutes shall be determined under finite mass conditions. These types are the Circular Flat, the Extended Skirt, the Ring-slot and the Circular Flat Ribbon parachute. The pressure distribution during filling and at steady state shall be related to the instantaneous canopy profile. Furthermore, an attempt shall be made to establish a general relationship between canopy profile and pressure distribution. The snatch velocity shall be held constant at approximately 110 knots, while the canopy loading shall be limited to the range between 0.3 and 0.7 lbs/ft2.

Author: C. Saliaris
Publisher:
ISBN:
Category : Parachutes
Languages : en
Pages : 8

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Book Description
The pressure distribution on the canopies of several types of parachutes shall be determined under finite mass conditions. These types are the Circular Flat, the Extended Skirt, the Ring-slot and the Circular Flat Ribbon parachute. The pressure distribution during filling and at steady state shall be related to the instantaneous canopy profile. Furthermore, an attempt shall be made to establish a general relationship between canopy profile and pressure distribution. The snatch velocity shall be held constant at approximately 110 knots, while the canopy loading shall be limited to the range between 0.3 and 0.7 lbs/ft2.

Author: H. D. Melzig
Publisher:
ISBN:
Category : Parachutes
Languages : en
Pages : 94

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Book Description
An experimental investigation was conducted to determine the differential pressure distribution over the surface of parachute canopies during the period of inflation under mass conditions. Full scale parachute canopies of the circular flat, 10% extended skirt, ringslot and ribbon types were utilized during the free-flight test program, and differential pressures on the gore centerline and on the cord line were measured by means of four pressure transducers distributed over the canopy in equal distances from the skirt to the vent. In order to analyze the relationships and dependencies between the pressure distribution, projected canopy area, canopy shape, generated force, and dynamic pressure, graphical displays of these quantities were made as a function of time for each type of parachute canopy. The results of the pressure distribution measurements permit a better understanding of the physical nature of the dynamic process of parachute inflation. The stress distribution in a parachute canopy can be calculated if the corresponding canopy shape is known. For this purpose, the evolvement of the canopy shape with the corresponding time is presented for each of the canopy types. (Author).

Author: H. D. Melzig
Publisher:
ISBN:
Category : Parachutes
Languages : en
Pages : 78

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Book Description
An experimental investigation and correlative analysis were conducted to determine the pressure distribution over the surface of parachute canopies during the period of inflation for the infinite mass case and to correlate pressure coefficients with inflating canopy shapes. Parachute canopy models of Circular Flat, 10% Extended Skirt, Ringslot, and Ribbon designs were tested under infinite mass conditions in a 9 x 12 ft low speed wind tunnel. External and internal pressure values were measured at various locations over the surface of the model canopies throughout the period of inflation, and generalized canopy profile shapes were obtined by means of photographic analysis.

Author: H.-D. Mlzig
Publisher:
ISBN:
Category : Aerodynamics
Languages : en
Pages : 16

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Book Description
For a design engineer strength calculation is a prerequisite for completion of design. The parachute designer however encounters great difficulty. Theory provides no means for calculation and almost no data is available of measurements under dynamic conditions to permit adequate strength calculation. The rapidly changing dynamic forces can vastly exceed the steady state forces. Great efforts have been made to predict stresses in a parachute canopy. The latest work for a parachute stress analysis was conducted by H.G. Heinrich and L.R. Jamison [1] and is a great advance. Contrary to former attempts it includes parachute shapes during inflation of the canopy. The great disadvantage of all theoretical attempts is that the actual stress distribution in a canopy is still unknown. No method has yet been found to measure stresses directly in many parts of a canopy.

Author: Eugene L. Haak
Publisher:
ISBN:
Category : Parachutes
Languages : en
Pages : 56

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Book Description
Conventionally shaped Ribbon parachutes do not function satisfactorily as aerodynamic decelerators in supersonic flow. Particularly objectionable is their unstable behavior. In order to determine the cause of this structural and dynamic instability, a series of pressure distribution measurements were made on ribbon parachutes at Mach numbers of 0.8, 1.2, 3.0, and 4.5. This report presents the results of measurements and attempts to indicate the effect of suspension lines and forebodies on the pressure distribution of the parachute canopy.

Author: Eugene L. Haak
Publisher:
ISBN:
Category : Aerodynamic load
Languages : en
Pages : 38

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Book Description
Wind tunnel studies were performed on six models representing opening stages of a Para-Sail parachute to establish the static pressure distribution on the internal and external surfaces of the inflating canopy. From this data, the maximum pressure differences across the parachute cloth have been calculated to be approximately equal to the dynamic pressure during early stages of inflation, and show a general increase to about twice this value as the canopy approaches the fully inflated condition.