(Review experimental scaling) A lightweight parachute is being designed for military use. Its diameter D is 20 ft and the total weight W of the falling payload, parachute, and equipment is 190 lb. The design terminal settling speed V. (or terminal velocity) of the parachute at this weight is 16 ft/'s. A one-twelfth scale model of the parachute is tested in a wind tunnel. The wind tunnel temperature and pressure are the same as those of the prototype, which is 70 °F and standard atmospheric pressure. a) Calculate the drag coefficient of the prototype. (Hint: At terminal velocity, speed is constant so weight is in equilibrium with aerodynamic drag.) b) At what speed should the wind tunnel be run in order to achieve dynamic similarity? c) Find the aerodynamic drag force of the model parachute in the wind tunnel in pounds.

Elements Of Electromagnetics
7th Edition
ISBN:9780190698614
Author:Sadiku, Matthew N. O.
Publisher:Sadiku, Matthew N. O.
ChapterMA: Math Assessment
Section: Chapter Questions
Problem 1.1MA
icon
Related questions
Question
**Design of a Lightweight Parachute for Military Use**

A lightweight parachute is being developed for military applications. Key specifications include:

- **Diameter \( D \):** 20 ft
- **Total weight \( W \):** 190 lb (including payload, parachute, and equipment)
- **Terminal settling speed \( V_t \):** 16 ft/s for the full-scale parachute

A one-twelfth scale model of the parachute is tested in a wind tunnel. The environmental conditions for the test (temperature and pressure) are identical to those for the full-scale prototype, set at 70°F with standard atmospheric pressure.

### Tasks

**a) Calculation of Drag Coefficient**

- Determine the drag coefficient of the prototype with the assumption that at terminal velocity, the weight is balanced with aerodynamic drag.

**b) Wind Tunnel Speed for Dynamic Similarity**

- Establish the wind tunnel speed required to achieve dynamic similarity with the scale model.

**c) Aerodynamic Drag Force on Model**

- Compute the aerodynamic drag force acting on the model parachute within the wind tunnel in pounds.

### Diagram Overview

The provided diagram illustrates the parachute system. It includes the parachute canopy, the payload, and the effective terminal velocity \( V_t \). The diameter \( D \) is indicated at the top of the parachute.

This structured approach to evaluating parachute dynamics ensures accuracy and performance under specified conditions.
Transcribed Image Text:**Design of a Lightweight Parachute for Military Use** A lightweight parachute is being developed for military applications. Key specifications include: - **Diameter \( D \):** 20 ft - **Total weight \( W \):** 190 lb (including payload, parachute, and equipment) - **Terminal settling speed \( V_t \):** 16 ft/s for the full-scale parachute A one-twelfth scale model of the parachute is tested in a wind tunnel. The environmental conditions for the test (temperature and pressure) are identical to those for the full-scale prototype, set at 70°F with standard atmospheric pressure. ### Tasks **a) Calculation of Drag Coefficient** - Determine the drag coefficient of the prototype with the assumption that at terminal velocity, the weight is balanced with aerodynamic drag. **b) Wind Tunnel Speed for Dynamic Similarity** - Establish the wind tunnel speed required to achieve dynamic similarity with the scale model. **c) Aerodynamic Drag Force on Model** - Compute the aerodynamic drag force acting on the model parachute within the wind tunnel in pounds. ### Diagram Overview The provided diagram illustrates the parachute system. It includes the parachute canopy, the payload, and the effective terminal velocity \( V_t \). The diameter \( D \) is indicated at the top of the parachute. This structured approach to evaluating parachute dynamics ensures accuracy and performance under specified conditions.
Expert Solution
trending now

Trending now

This is a popular solution!

steps

Step by step

Solved in 2 steps

Blurred answer
Knowledge Booster
Dimensional Analysis
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, mechanical-engineering and related others by exploring similar questions and additional content below.
Similar questions
  • SEE MORE QUESTIONS
Recommended textbooks for you
Elements Of Electromagnetics
Elements Of Electromagnetics
Mechanical Engineering
ISBN:
9780190698614
Author:
Sadiku, Matthew N. O.
Publisher:
Oxford University Press
Mechanics of Materials (10th Edition)
Mechanics of Materials (10th Edition)
Mechanical Engineering
ISBN:
9780134319650
Author:
Russell C. Hibbeler
Publisher:
PEARSON
Thermodynamics: An Engineering Approach
Thermodynamics: An Engineering Approach
Mechanical Engineering
ISBN:
9781259822674
Author:
Yunus A. Cengel Dr., Michael A. Boles
Publisher:
McGraw-Hill Education
Control Systems Engineering
Control Systems Engineering
Mechanical Engineering
ISBN:
9781118170519
Author:
Norman S. Nise
Publisher:
WILEY
Mechanics of Materials (MindTap Course List)
Mechanics of Materials (MindTap Course List)
Mechanical Engineering
ISBN:
9781337093347
Author:
Barry J. Goodno, James M. Gere
Publisher:
Cengage Learning
Engineering Mechanics: Statics
Engineering Mechanics: Statics
Mechanical Engineering
ISBN:
9781118807330
Author:
James L. Meriam, L. G. Kraige, J. N. Bolton
Publisher:
WILEY