# HW4_solutions - ECE 333 Homework 4 Solutions Spring 2010 1...

This preview shows pages 1–2. Sign up to view the full content.

ECE 333 Homework 4 Solutions :: Spring 2010 1 A horizontal-axis wind turbine with rotor 20 meters in diameter is 30-percent efficient in 10 m/s winds at 1 atmosphere of pressure and 15 o C temperature. a. How much power would it produce in those winds? P !"# P wind !"# 1 2 \$ A v 3 ! 0.3 " 1 2 1.225 # 4 20 2 10 3 ! P \$ 57.73 kW b. Estimate the air density on a 2500-meter mountaintop at 10 o C. From Table 6.1 the density at 10 o C is 1.247 kg/m 3 , yielding a K T ratio of 1.247/1.225 = 1.018. Using (6.13), the density ratio, K A , can be found: P ! P 0 exp !" 1.185x10 " 4 # 2500 \$% 0.9109 K A ! 0.9109 1.225 ! 0.743 The air density at 2500-meters can now be found using (6.14): "! 1.225 K T K A ! 1.225 " 1.018 " 0.743 #\$! 0.927 kg % m 3 Note that (6.7) could also be used to find the same solution. c. Estimate the power the turbine would produce on that mountain with the same windspeed assuming its efficiency is not affected by air density.

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

## This note was uploaded on 03/04/2011 for the course ECE 333 taught by Professor Overby during the Spring '09 term at University of Illinois, Urbana Champaign.

### Page1 / 2

HW4_solutions - ECE 333 Homework 4 Solutions Spring 2010 1...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online