3.

OBJECTIVE:

·

We

have come across with an idea of generating power in a traditional way and

utilizing that energy for an efficient mode of transportation.

·

The

automobile industry is emerging in manufacturing electric cars by utilizing few

components of electric devices such as 3phase induction motor, inverter and the

power house which can be regular lithium ion batteries as in the case for tesla

motors or modified battery packs as in Nissan leaf.

·

These

electric cars having plenty of space because of un presence of IC engines which

traditional vehicles generally run with.

·

Our

main objective is to install either the vortex bladeless concept or a small

wind turbine with a generator of size of a normal household use in the empty

space of those electric cars in the front portion.

·

Both

the wind turbine concept and the vortex bladeless concept starts at the moment

when the free stream air or the head wind strikes the blades in case of wind

turbine or when the air enters into the conduit in the case of vortex bladeless

concept.

·

Design

of the front portion should be in such a way that the head wind hits the blades

or enters into the conduit with a uniform flow in order to avoid the vibration

and mechanical damages of the system.

Fig : https://electrek.co/guides/tesla-model-s

METHODOLOGY :

As we discussed earlier

our objective is to install a small scale turbine which eventually becomes

power producing source for the prospective vehicle. The size (diameter) and the

corresponding desired power output are the main concern for our project. Let’s

take the example, the Tesla model S: It has the battery pack of 100kwh and runs

approximately 500-510km that shows the vehicle consuming 20kwh for every 100km

approximately. Let’s estimate the scale of the turbine which can increase the

range of the considered vehicle and we will see how much the increment in range

at different speeds by generating the power.

Let’s say,

Diameter of the rotor D

=0.50m

Mechanical efficiency ?m =0.9

Electrical efficiency ?e =0.95

Considering the free

stream velocity or head wind in this case is at 60kmph.

Considering the

velocity losses at the intake let’s consider the speed reduced to (V) 40kmph or

11.2m/s.

Power output P = (power contained in wind * power

coefficient*mechanical efficiency*electrical efficiency)

P=P0*Cp*?m*?e ……..(a)

Where

P0=1/2*?*A*V3

Substitute P0 in equation (a), we get

P=1/8*?*?*D2*V3* Cp* ?m* ?e

Cp=0.2

(least value considered)

P=1/8*1.22* ?*0.52*11.23*0.2*0.9*0.95

P=28.77W

This is the output

power generated by the wind turbine with the rotor diameter meter 0.5m. At the

speed of 11.2m/s the wind turbine generating the power of 28.77W or 28.77ws in

terms of energy, which concludes that if vehicle runs for 1 hour at 11.2m/s

speed the turbine can be able to produce 100kwh. This is the capacity of main

battery pack which in turn shows that the vehicle can run again for 500km

(assuming that vehicle runs at constant speed 11.2m/s).

If Cp is

taken as 0.1 the generating output will become

P=1/8*1.22* ?*0.52*11.23*0.1*0.9*0.95

P=14.39 W

For Cp=0.1, 14.39

W power or 14.39W-S energy generated at 11.2m/s. For 1 hour the turbine can be

able to produce

E=14.39*3 600

E=51.804 KWH

With

the 51KWH the vehicle can run for another 250km.The power generated would be AC

and it can be directly connect to the induction motor which drives the drive

wheel or for charging the battery pack which is our main concern.

Apart

from the output power there are certain parameters which should be consider for

the effective energy extraction while working under different conditions such

as turbulence in the wind, stresses and bending forces and other load forces.

Some of the turbulence models for calculating the turbulence are discussed

below:

Stochastic

turbulence models:

The following stochastic turbulence models

may be used for design load calculations. The turbulent velocity fluctuations

are assumed to be

a random vector field whose components

have zero-mean Gaussian statistics. The power spectral densities describing the

components are given in terms of the Kaimal spectral and exponential coherency

model or by the Von Karman isotropic model.

Kaimal spectral

model

The component power spectral densities are

given in non-dimensional form by the equation:

where

f is the frequency in

Hertz;

k is the index referring to

the velocity component direction (i.e. 1 = longitudinal, 2 =lateral, and 3 =

vertical);

Sk the single-sided velocity

component spectrum;

? kis

the velocity component standard deviation (see Equation (C.2)); and

Lk is the velocity

component integral scale parameter.

and

with

C.2 Exponential coherency model

The

following exponential coherency model may be used in conjunction with the

Kaimal autospectrum model to account for the spatial correlation structure of

the longitudinal velocity component:

where

Coh(r,f) is the coherency function defined by the complex magnitude of the

cross spectral density of the longitudinal wind velocity components at two

spatially separated points divided by the autospectrum function;

r is the magnitude of the projection of the separation vector between

the two

points

on to a plane normal to the average wind direction;

f is the frequency in Hertz; and

Lc = 3,5?1 is the

coherency scale parameter.

C.3 Von Karman isotropic turbulence model

The

longitudinal velocity component spectrum is given in this case by the

non-dimensional equation:

where

f is the frequency in Hertz;

L = 3,5?1 is the

isotropic integral scale parameter; and

?1 is the longitudinal standard deviation at hub height.

The lateral and vertical

spectra are equal and given in non-dimensional form by:

where

L is the same isotropic scale parameter as used in Equation (C.4); and

?2

= ?3

= ?1,

are the wind speed standard deviation components.

The coherency is given by:

Where

r

is

the separation between the fixed points;

L is the isotropic turbulence integral scale;

? (.) is the gamma function; and

K(.)(.) is the fractional-order, modified Bessel function

.

Equation (C.6) can be approximated by the

exponential model given in Equation (C.3), with Lc replaced by the isotropic scale parameter L.