# Recent content by ruzfactor

1. ### Calorific value of Petrol

Actually I wanted to know if a country ,for example, chooses to extract petrol from liquefaction of coal over cracking of crudeoil, will the petrol be the same as (in terms of energy content) from crude oil.
2. ### Calorific value of Petrol

Thanks for the reply. The link you referred gives heating value of many fuels. Is there any source where I can get heating values of petrol extracted from crude oil and, from liquefaction of coal. Are they really different?
3. ### Calorific value of Petrol

Hi I am bit confused regarding the heating/calorific value of petrol (used for vehicle) extracted from crude oil and from liquefaction of coal. Should they be same? or Petrol extracted from crude oil will have different calorific value compared to the petrol from liquefaction...
4. ### Wave Propagation in Vibrating Solid

Hi I am very confused at determining the type of elastic wave in a vibrating body. For example, an elastic solid is flexuraly vibrating in one of its resonant mode. There should be elastic wave excited from this vibration. But, my question is which wave will be excited through it...
5. ### Numerical Integration of Double integrals

Is my way of doing the double integration correct using the trapezoidal rule?
6. ### Numerical Integration of Double integrals

so the unit would depend on the unit I am considering for the function. Although the integral is not computing an area but the integral is found from the area of the curve drawn from the function along its limits numerically. e.g. ∫x^3dx= x^4/4 [m^4] (limit say 0 to 5) So I can evaluate it...
7. ### Numerical Integration of Double integrals

Please see the attached for the function psi.
8. ### Numerical Integration of Double integrals

I have a double integral: ∫∫sin^2(∏x/A)*sin^2(∏y/B)dxdy A=length along x B=length along y ranges: 0 to A(for x) & 0 to B (for y) Analytical result is: A*B/4 (unit^2) Now, I want to evaulate it numerically using trapezoidal rule. Infact, I have done it but not sure whether it is a right...
9. ### Polar Integration

Thanks. Actually the problem says that, integrate f(r,θ) in radial and circumferential direction. So it is a bit confusing. I guess rdrdθ could be used depending on my problem. Here, the function f(r,θ) is the mode shape function of a circular plate.
10. ### Polar Integration

Thanks. I have a function of r. For example at theta=0, the value of the function have different value at different r values (e.g. r=0 to r=a). I want to evaluate this function over 2∏. So I thought first integrating the function about r and then theta. That is where I am confused, whether to...
11. ### Polar Integration

Hi I have a function [e.g. f(r)] which I want to integrate over r and θ. What would be the integration form? Which one is correct? ∫∫f(r) drdθ OR ∫∫f(r) rdrdθ Please explain. Also, can it be said as area integration as well like the one in cartesian coordinate?
12. ### Area of the Curve

Hi How can I calculate the area of the shaded region in picture attached? Please suggest.
13. ### Increasing Heat Transfer Area

Is there any effect on temperature, when a flow experience sudden enlargement?
14. ### Increasing Heat Transfer Area

Heat transfer is much less in case of low flow rate. I need the reactor to be heated within a shorter period. But it all failed. A new design is the only solution I guess. Is the heat capacity of damp air higher than the dry air? How can I prove (theoretically) that damp air could improve heat...
15. ### Transient Heat Transfer in Radial Direction

Yes the purpose of the fins is to make uniform temperature profile. How can I explain this phenomenon with my geometry? Could you please help? Is is beacuse of a shorter heat path for heat conduction from the walls?