Why this program is not working?

#include<>
using namespace std;

int main()

{
char ch;

cout<<"Enter any letter: ";
cin>>"ch";

if(ch=='a' || ch=='e' || ch=='i' || ch=='o' || ch=='u'|| ch=='A' || ch=='E' || ch=='I' || ch=='O' || ch=='U')
cout<<"Vowel";
else
cout<<"Consonant";

return 0;
}

Air is to be cooled in the evaporator section of a refrigerator by passing it over a bank of 0.8-cm-outer-diameter and 0.4-m-long tubes inside which the refrigerant is evaporating at -20°c. air approaches the tube bank in the normal direction at 0°c and 1 atm with a mean velocity of 4 m/s. the tubes are arranged in-line with longitudinal and transverse pitches of sl- st 1.5 cm. there are 30 rows in the flow direction with 15 tubes in each row. determine (a) the refrigeration capacity of this system and (b) pressure drop across the tube bank. evaluate the air properties at an assumed mean temperature of -5°c and 1 atm. is this a good assumption?

The air in an automobile tire with a volume of 0.015 m3 is at 32°c and 140 kpa gage. determine the amount of air that must be added to raise the pressure to the recommended value of 206 kpa gage. assume the atmospheric pressure to be 128 kpa and the temperature and the volume to remain constant.[r-0.287 kj/kgk]

Agas contained within a piston-cylinder assembly e end nation about same energy states, 1 and 2, where pi 10 bar, v undergoes two processes, a and b, between the sam 0.1 m3, ui-400 kj and p2 1 bar, v2 1.0 m2, u2 200 kj: process a: process from 1 to 2 during which the pressure- volume relation is pv constant process b: constant-volume process from state 1 to a pressure of 2 bar, followed by a linear pressure-volume process to +20 0 state 2 kinetic and potential energy effects can be ignored. for each of the processes a and b, (a) sketch the process on p-v coordinates, (b) evaluate the work, in kj, and (c) evaluate process the heat transfer, in kj