Both the work of expansion and the work of flow are functions of the process, whether the function o

1. Expansion work: δW=PDV, that is, W= PDV, so the expansion work is the area enclosed by the process curve and the V-axis projection; 2. Technical work: δwt=-vdp, so wf=- vdp, so technical work is the negative value of the area enclosed by the process curve and the p-axis projection; 3. Flow work:

wf=d(pv)=pdv+vdp, i.e. wf= pdv-(vdp)=w - wt, so the flow work is the difference between the expansion work and the technical work; 4. The problem of the size of technical work and expansion work. (1) The size of the two is related to the path, but the two are closely related. For example, the relationship between the expansion work and the technical work of the changeable process is:

wt=n where n is the multivariant process index. (2) Obviously, the magnitude of the technical work and the expansive work is determined by the variable exponent n. When n 1, the expansion work is greater than the technical work, such as isobaric process, n=0, wt=0, but w=p(v2-v1) When n =1, the expansion work is equal to the technical work, that is, the isothermal process, the two are equal When n 1, the expansion work is less than the technical work, such as the isochoric process, n + w=0, but wt=v(p2-p1) 5, Note:

The above are all reversible processes, but in terms of the size of the two, the relationship with reversibility is not so close, and it is mainly related to the process.

False, the flow work is a state quantity.

1. The difference between the two.

1. Conceptual differences.

1) Expansion work infiltration chain: the output of work through the change of the specific volume of the working fluid is called expansion work.

2) Technician: Technically, the work that can be used by Cong Lusun is called technical work.

2. The calculation formula is different.

Under reversible conditions, the formulas for both are as follows:

1) Expansion work: w= p dv

2) Technical work: wt=ws+( c 2) 2+g z=- v dp (the front is the definition, the back is the derivation).

Second, the relationship between the two.

Under reversible conditions, ideal gas.

The relationship between the work of expansion and the work of technology is:

wt=n×w

where n is the variable exponent. The following is a discussion of n.

1) When n=0, it is an isobaric process, at this time, wt=0, w=p v2)n=1, it is an isothermal process, at this time, wt=w=rgtln(v2 v1)3)n=k, it is an isentropic process, at this time, wt=k w=k (k-1) rg (t1-t2).

4) n, for the isovolume process, at this time, wt= p v, w = 0 above for the landlord's reference.

The work done by gas expansion cannot be calculated by δt, but must be calculated by the change of external energy.

For example, if you push a 1kg piston 1 meter higher, you can calculate that the gas expansion does 10J of work.

It can be calculated by the change in the gravitational potential energy of the piston and the change in the elastic potential energy of the spring.

Piston mass m, then gas work = mgh + kh 2

Expansion work (also known as collapse volume slag and work) - the work done by a gas due to a change in volume during thermal processes. Therefore, on the P-V diagram, W12 is the area enclosed by the process line and the horizontal axis. Provisions: The thermal system does work on the outside world.

is positive, and the work done by the outside world on the thermal system is negative. From δW=PDV: DV>0, expansion, ΔW>0, the system does work on the outside world; DV<0, compression, δw<0, the outside world does work on the system; dv=0, δw=0, reactive power transfer between the system and the outside world.

When the gas expands, the external work is done, the internal energy of the gas decreases, the temperature decreases, and the internal energy is converted into mechanical energy

Therefore, C

Since the work is the process quantity, the mobile work is also the front range of the antechamber.

a.That's right. b.Mistake.

Correct answer: False.