
We discuss coupling conditions for the p-system in case of a transition from supersonic states to subsonic states. A single junction with adjacent pipes is considered where on each pipe the gas flow is governed by a general p-system. By extending the notion of demand and supply known from traffic flow analysis we obtain a constructive existence result of solutions compatible with the introduced conditions.
Citation: Martin Gugat, Michael Herty, Siegfried Müller. Coupling conditions for the transition from supersonic to subsonic fluid states[J]. Networks and Heterogeneous Media, 2017, 12(3): 371-380. doi: 10.3934/nhm.2017016
[1] | Martin Gugat, Michael Herty, Siegfried Müller . Coupling conditions for the transition from supersonic to subsonic fluid states. Networks and Heterogeneous Media, 2017, 12(3): 371-380. doi: 10.3934/nhm.2017016 |
[2] | Jens Lang, Pascal Mindt . Entropy-preserving coupling conditions for one-dimensional Euler systems at junctions. Networks and Heterogeneous Media, 2018, 13(1): 177-190. doi: 10.3934/nhm.2018008 |
[3] | Yannick Holle, Michael Herty, Michael Westdickenberg . New coupling conditions for isentropic flow on networks. Networks and Heterogeneous Media, 2020, 15(4): 605-631. doi: 10.3934/nhm.2020016 |
[4] | Christophe Chalons . Theoretical and numerical aspects of the interfacial coupling: The scalar Riemann problem and an application to multiphase flows. Networks and Heterogeneous Media, 2010, 5(3): 507-524. doi: 10.3934/nhm.2010.5.507 |
[5] | Rinaldo M. Colombo, Francesca Marcellini . Coupling conditions for the $3\times 3$ Euler system. Networks and Heterogeneous Media, 2010, 5(4): 675-690. doi: 10.3934/nhm.2010.5.675 |
[6] | Steinar Evje, Kenneth H. Karlsen . Hyperbolic-elliptic models for well-reservoir flow. Networks and Heterogeneous Media, 2006, 1(4): 639-673. doi: 10.3934/nhm.2006.1.639 |
[7] | Raul Borsche, Axel Klar, T. N. Ha Pham . Nonlinear flux-limited models for chemotaxis on networks. Networks and Heterogeneous Media, 2017, 12(3): 381-401. doi: 10.3934/nhm.2017017 |
[8] | Yogiraj Mantri, Michael Herty, Sebastian Noelle . Well-balanced scheme for gas-flow in pipeline networks. Networks and Heterogeneous Media, 2019, 14(4): 659-676. doi: 10.3934/nhm.2019026 |
[9] | Rinaldo M. Colombo, Graziano Guerra . A coupling between a non--linear 1D compressible--incompressible limit and the 1D $p$--system in the non smooth case. Networks and Heterogeneous Media, 2016, 11(2): 313-330. doi: 10.3934/nhm.2016.11.313 |
[10] | Jean-Marc Hérard, Olivier Hurisse . Some attempts to couple distinct fluid models. Networks and Heterogeneous Media, 2010, 5(3): 649-660. doi: 10.3934/nhm.2010.5.649 |
We discuss coupling conditions for the p-system in case of a transition from supersonic states to subsonic states. A single junction with adjacent pipes is considered where on each pipe the gas flow is governed by a general p-system. By extending the notion of demand and supply known from traffic flow analysis we obtain a constructive existence result of solutions compatible with the introduced conditions.
Natural gas pipeline transportation systems are an important part of our infrastructure. Besides transport of gas, also
∂tρ(t,x)+∂xq(t,x)=0,∂tq(t,x)+∂x(q2(t,x)ρ(t,x)+p(ρ(t,x)))=0, | (1) |
where
It has been shown that the transversality condition is fulfilled for subsonic data, i.e. initial conditions
p(ρk(t,0+))=p∗(t)∀k∈δ+,p(ρk(t,0−))=p∗(t)∀k∈δ−, | (2a) |
∑k∈δ−qk(t,0−)=∑k∈δ+qk(t,0+). | (2b) |
for some unknown nodal pressure
The study of the coupling of subsonic and supersonic flow is also important for algorithmic purposes. For example in an iterative method for the solution of optimal control problems (see for example [7]), it can happen that during the iteration in an intermediate step, supersonic states appear even if the optimal state is subsonic. The transition from supersonic to subsonic flow is important for high-speed aircraft, where a supersonic external freestream flow must be decelerated efficiently to subsonic speed at the turbine inlet. This transition from supercritical flow to subcritical flow also occurs in Fanno flows, see [22], (p. 199). The transition from supercritical to subcritical regime in free surface flow of yield stress fluids has been studied in [23] where a hydraulic jump during laminar flow of an Herschel-Bukley fluid in a rectangular channel is studied. An experimental assessment of scale effects affecting two-phase flow properties in hydraulic jumps is given in [20].
In this work we will introduce a notion of supply and demand for the state of the system on the adjacent pipes similar to the notion in traffic flow [19,14]. This will allow to solve for constant initial data
We recall the Lax-curves for the p-system for a pressure law satisfying the following assumption on the equation of state, i.e.
p′(ρ)>0, p″(ρ)≥0, | (3a) |
6p′(ρ)+3p″(ρ)(ρ−ˉρ)+ρ(3p″(ρ)+(ρ−ˉρ)p‴(ρ))>0∀ρ>ˉρ≥0 | (3b) |
and such that
ρp″(ρ)+2p′(ρ)>0, | (4) |
see e.g. [9,5]. This also implies that both characteristic fields are genuinely nonlinear. In addition, the second condition (3b) is required later in order to obtain strict convex (resp. concave) wave curves. The assumptions (3) are fulfilled by the pressure law of the isentropic Euler equations
Under the assumption (3a) the p-system (1) is strictly hyperbolic in the non-vacuum states
λ1(U)=qρ−c(ρ), λ2(U)=qρ+c(ρ). | (5) |
Both characteristic fields are genuinely nonlinear if the equation of state fulfills (4) and (3a). The 1-Lax-curve through
L1(σ;ˉU)=(R1(σ;ˉU)σ≤ˉρS1(σ;ˉU)σ>ˉρ). | (6) |
The reversed 2-Lax-curve through
L−2(σ;ˉU)=(S2(σ;ˉU)σ>ˉρR2(σ;ˉU)σ≤ˉρ). | (7) |
Here, for
Si(σ;ˉU)=σ ˉqˉρ∓√σˉρ(σ−ˉρ)(p(σ)−p(ˉρ)),Ri(σ;ˉU)=σˉqˉρ∓σ∫σˉρc(s)sds. |
The precise form and derivation of the curves can be found e.g. in [9,13]. Therein, also the following properties are established: The shock curves
From the explicit form of
d2dσ2Ri(σ,ˉU)=∓(σp″(σ)+2p′(σ)2σ√p′(σ)). |
Since
s″(σ)=2σˉρp′(σ)+2ˉρ(p(σ)−p(ˉρ))+σ−ˉρˉρ(2p′(σ)+σp″(σ))>0. |
Hence,
d2dσ2Si(σ,ˉU)=∓12√s(σ)(s″(σ)−s′(σ)22s(σ)). |
The function
We also note that
s‴(σ)ˉρ=6p′(σ)+3p″(σ)(σ−ˉρ)+σ(3p″(σ)+(σ−ˉρ)p‴(σ))>0 |
provided that condition (3b) holds true. Then,
Under assumption (3b) we therefore obtain
Si is strictly concave and Ri is strictly convex,i=1,2. | (8) |
Hence,
We now define the demand and supply for the p-system extending the notion in the scalar case [19]. In the
d(ρ;ˉU)=(L1(ρ;ˉU),0<ρ≤min{ˉρ,ρ∗}ˉqH(ρ∗−ˉρ)+q∗H(ˉρ−ρ∗), else ) | (9) |
s(ρ;ˉU)=(L−2(ρ;ˉU)H(ρ−ρ∗)−q∗H(ρ∗−ρ),ˉρ>ρ∗ˉqH(ˉρ−ρ)+H(ρ−ˉρ)max{ˉq,L−2(ρ;ˉU)},ˉρ<ρ∗). | (10) |
A sketch of the supply and demand for different states
The demand and supply are used to determine admissible fluxes for waves of non-positive and non-negative speed, respectively. A Riemann problem is a Cauchy problem for equation (1) and initial data
Theorem 2.1. Let
Proof. We have to distinguish two cases. Suppose
In the case
Corollary 1. Let
The proof is similar to the proof of Theorem 2.1 and omitted. It should be noted that in the formulation of Corollary 1 the right state
We introduce the following subsets of
A+:={U:=(ρ,q):λi(U)>0,i=1,2}, | (11) |
A:={U:=(ρ,q):λ1(U)<0<λ2(U)},A−:={U:=(ρ,q):λi(U)<0,i=1,2}. | (12) |
The set
∂t(ρk(t,x)qk(t,x))+∂x(qk(t,x)q2k(t,x)ρk(t,x)+p(ρk(t,x)))=0,Uk(t,0)=(U−kx<0U+kx>0). | (13) |
Depending on the pipe only one of the Riemann data is defined at
The demand and supply allows to construct solutions of certain wave speeds. Consider
In order to obtain a unique density at the node we define the function
k∈δ−:τk(ˉU):=(ρ∗(ˉU) if ˉρ≥ρ∗(ˉU),˜ρ else), where ˜ρ≠ˉρ and L1(˜ρ;ˉU)=ˉq. | (14a) |
Similarly,
k∈δ+:τk(ˉU)=(ρ∗(ˉU) if ˉρ≥ρ∗(ˉU),˜ρ else), where ˜ρ≠ˉρ and L−2(˜ρ;ˉU)=ˉq. | (14b) |
Clearly,
Finally, we turn to the description of the Riemann solver for problem (13) and (2). Due to assumption (3) we have that the condition (2) is equivalent to
ρk(t,0+)=ρk′(t,0−)∀k∈δ+,k′∈δ−, | (15) |
and
∑k∈δ−qk(t,0−)−∑k∈δ+qk(t,0+)=0. | (16) |
Note that in the case
q−1(t,0−)=q1(t,0+),q2−1(t,0−)ρ−1(t,0−)+p(ρ−1(t,0−))=q21(t,0+)ρ1(t,0+)+p(ρ1(t,0+)). |
For consistency a solution to (13) should therefore be also a solution to a (classical) Riemann problem for (1) with initial data
We are interested in supersonic and subsonic coupling at the junction. Therefore, we assume in the following that
U−k=U0,k∈A+ for k∈δ−,U+k=U0,k∈A for k∈δ+. | (17) |
Remark 1. Due to the symmetry of the Lax curves for the p-system, the discussion also includes the case where
We now plan to construct a solution fulfilling the coupling conditions. As preliminary result we prove the monotonicity of the Lax curves.
Lemma 2.2. Assume
Then, for all
Proof. In the case
In general, under assumption (17), the solution to a Riemann problem for (1) consists of a superposition of waves of the first family and waves of the second family. In order to solve the problem (13) we mimic this behavior by constructing of a solution as follows. Denote by
σlb:=maxk∈δ±τk(U0,k). | (18) |
Then, equation (16) is fulfilled provided that there exists
∑k∈δ−L1(σ;U0,k)−∑k∈δ+L−2(σ;U0,k)=0. | (19) |
The following Theorem guarantees the solvability of the previous equation and presents the main result.
Theorem 2.3. Assume
Provided that
∑k∈δ−L1(σlb;U0,k)≥∑k∈δ+L−2(σlb;U0,k) | (20) |
there exists a unique
The proof follows immediately from the monotonicity properties established before.
Now, we continue our construction: Suppose (19) has a unique solution
U+k:=(¯σ,L1(¯σ;U0,k))T,k∈δ−,U−k:=(¯σ,L−2(¯σ;U0,k))T,k∈δ+. | (21) |
Then, we have
Some remarks are in order.
Remark 2. Note that this construction is also valid in the case
In the case
Remark 3. Note that linearization techniques in order to solve (2) and (16) will fail to provide a solution to (13) due to the fact that at
In the case
We consider
Pipe | ||
-1 | (5.151e-01, 2.519e+00) | 2.653e-01 |
-2 | (6.317e-01, 2.794e+00) | 3.991e-01 |
-3 | (6.642e-01, 3.905e+00) | 4.412e-01 |
1 | (5.730e-01, -2.648e-01) | 3.283e-01 |
2 | (7.460e-01, -1.523e-01) | 5.565e-01 |
3 | (5.931e-01, -1.280e-01) | 3.518e-01 |
4 | (5.849e-01, 6.020e-01) | 3.421e-01 |
Pipe | ||
-1 | (2.089e+00, 5.101e+00) | 4.364e+00 |
-2 | (2.089e+00, 4.868e+00) | 4.364e+00 |
-3 | (2.089e+00, 8.090e+00) | 4.364e+00 |
1 | (2.089e+00, 3.757e+00) | 4.364e+00 |
2 | (2.089e+00, 3.357e+00) | 4.364e+00 |
3 | (2.089e+00, 4.147e+00) | 4.364e+00 |
4 | (2.089e+00, 6.798e+00) | 4.364e+00 |
While coupling conditions for the subsonic flow in gas pipelines are well-established, in this paper the coupling conditions for the transonic transition from supersonic flow to subsonic flow are studied that have not been thoroughly analyzed before. In this way we fill a gap in the theory, which is important in order to have a complete theory that covers all cases. This can also be important for algorithmic purposes, since during an iterative method for the solution of an optimal control problem, it may happen that supersonic states occur, even if the optimal state is subsonic. The purely subsonic case has been treated explicitly in [1] and in general e.g. in [8]. For a complete theory of all possible cases the fully supersonic case is still at large. Future work may then include a complete statement provided the challenges in the supersonic regime can be dealt with.
[1] |
Coupling conditions for gas networks governed by the isothermal Euler equations. Netw. Heterog. Media (2006) 1: 295-314 (electronic). ![]() |
[2] |
Gas flow in pipeline networks. Netw. Heterog. Media (2006) 1: 41-56. ![]() |
[3] | A. Bressan, Hyperbolic Systems of Conservation Laws, The One-Dimensional Cauchy Problem, Oxford Lecture Series in Mathematics and its Applications, 20, Oxford University Press, Oxford, 2000. |
[4] |
Flow on networks: recent results and perspectives. European Mathematical Society-Surveys in Mathematical Sciences (2014) 1: 47-111. ![]() |
[5] |
The Cauchy problem for the Euler equations for compressible fluids. Handbook of Mathematical Fluid Dynamics (2002) 1: 421-543. ![]() |
[6] |
Traffic flow on a road network. SIAM J. Math. Anal. (2005) 36: 1862-1886 (electronic). ![]() |
[7] |
Optimal control in networks of pipes and canals. SIAM J. Control Optim. (2009) 48: 2032-2050. ![]() |
[8] |
A well posed Riemann problem for the p-system at a junction. Netw. Heterog. Media (2006) 1: 495-511. ![]() |
[9] |
On the Cauchy problem for the p-system at a junction. SIAM J. Math. Anal. (2008) 39: 1456-1471. ![]() |
[10] |
On 2×2 conservation laws at a junction. SIAM J. Math. Anal. (2008) 40: 605-622. ![]() |
[11] | Thèorie du mouvement non-permanent des eaux, avec application aux crues des rivière at à l'introduction des marèes dans leur lit.. C.R. Acad. Sci. Paris (1871) 73: 147-154. |
[12] | M. Garavello and B. Piccoli, Traffic Flow on Networks, vol. 1 of AIMS Series on Applied Mathematics, American Institute of Mathematical Sciences (AIMS), Springfield, MO, 2006, Conservation laws models. |
[13] |
E. Godlewski and P. -A. Raviart,
Numerical Approximation of Hyperbolic Systems of Conservation Laws, Applied Mathematical Sciences, 118, Springer-Verlag, New York, 1996. doi: 10.1007/978-1-4612-0713-9
![]() |
[14] |
Coupling conditions for a class of second-order models for traffic flow. SIAM J. Math. Anal. (2006) 38: 595-616. ![]() |
[15] |
Assessment of coupling conditions in water way intersections. Internat. J. Numer. Methods Fluids (2013) 71: 1438-1460. ![]() |
[16] |
A mathematical model of traffic flow on a network of unidirectional roads. SIAM J. Math. Anal. (1995) 26: 999-1017. ![]() |
[17] |
Riemann problems with a kink. SIAM J. Math. Anal. (1999) 30: 497-515 (electronic). ![]() |
[18] | S. Joana, M. Joris and T. Evangelos, Technical and Economical Characteristics of Co2 Transmission Pipeline Infrastructure, Technical report, JRC Scientic and Technical Reports, European Commission. |
[19] | Les modeles macroscopiques du traffic. Annales des Ponts. (1993) 67: 24-45. |
[20] |
Experimental assessment of scale effects affecting two-phase flow properties in hydraulic jumps. Experiments in Fluids (2008) 45: 513-521. ![]() |
[21] |
Simulation of transient flow in gas networks. Int. Journal for Numerical Methods in Fluid Dynamics (1984) 4: 13-23. ![]() |
[22] | B. Sultanian, Fluid Mechanics: An Intermediate Approach, CRC Press, 2015. |
[23] |
R. Ugarelli and V. D. Federico, Transition from supercritical to subcritical regime in free surface flow of yield stress fluids Geophys. Res. Lett. , 34 (2007), L21402. doi: 10.1029/2007GL031487
![]() |
1. | E. Fokken, S. Göttlich, O. Kolb, Modeling and simulation of gas networks coupled to power grids, 2019, 119, 0022-0833, 217, 10.1007/s10665-019-10026-6 | |
2. | EIKE FOKKEN, SIMONE GÖTTLICH, MICHAEL HERTY, Efficient simulation of coupled gas and power networks under uncertain demands, 2022, 0956-7925, 1, 10.1017/S0956792522000079 | |
3. | Andrea Corli, Ulrich Razafison, Massimiliano D. Rosini, Coherence and flow-maximization of a one-way valve, 2022, 56, 2822-7840, 1715, 10.1051/m2an/2022053 | |
4. | Georges Bastin, Jean-Michel Coron, Amaury Hayat, Peipei Shang, Boundary feedback stabilization of hydraulic jumps, 2019, 7, 24686018, 100026, 10.1016/j.ifacsc.2019.100026 | |
5. | Michael Herty, Siegfried Müller, Aleksey Sikstel, Coupling of Compressible Euler Equations, 2019, 47, 2305-221X, 769, 10.1007/s10013-019-00353-7 | |
6. | Martin Gugat, Michael Herty, 2022, 23, 9780323850599, 59, 10.1016/bs.hna.2021.12.002 | |
7. | Michael Herty, Niklas Kolbe, Siegfried Müller, Central schemes for networked scalar conservation laws, 2022, 18, 1556-1801, 310, 10.3934/nhm.2023012 | |
8. | Andrea Corli, Massimiliano D. Rosini, Ulrich Razafison, 2024, Mathematical Modeling of Chattering and the Optimal Design of a Valve*, 979-8-3503-1633-9, 76, 10.1109/CDC56724.2024.10886245 |
Pipe | ||
-1 | (5.151e-01, 2.519e+00) | 2.653e-01 |
-2 | (6.317e-01, 2.794e+00) | 3.991e-01 |
-3 | (6.642e-01, 3.905e+00) | 4.412e-01 |
1 | (5.730e-01, -2.648e-01) | 3.283e-01 |
2 | (7.460e-01, -1.523e-01) | 5.565e-01 |
3 | (5.931e-01, -1.280e-01) | 3.518e-01 |
4 | (5.849e-01, 6.020e-01) | 3.421e-01 |
Pipe | ||
-1 | (2.089e+00, 5.101e+00) | 4.364e+00 |
-2 | (2.089e+00, 4.868e+00) | 4.364e+00 |
-3 | (2.089e+00, 8.090e+00) | 4.364e+00 |
1 | (2.089e+00, 3.757e+00) | 4.364e+00 |
2 | (2.089e+00, 3.357e+00) | 4.364e+00 |
3 | (2.089e+00, 4.147e+00) | 4.364e+00 |
4 | (2.089e+00, 6.798e+00) | 4.364e+00 |
Pipe | ||
-1 | (5.151e-01, 2.519e+00) | 2.653e-01 |
-2 | (6.317e-01, 2.794e+00) | 3.991e-01 |
-3 | (6.642e-01, 3.905e+00) | 4.412e-01 |
1 | (5.730e-01, -2.648e-01) | 3.283e-01 |
2 | (7.460e-01, -1.523e-01) | 5.565e-01 |
3 | (5.931e-01, -1.280e-01) | 3.518e-01 |
4 | (5.849e-01, 6.020e-01) | 3.421e-01 |
Pipe | ||
-1 | (2.089e+00, 5.101e+00) | 4.364e+00 |
-2 | (2.089e+00, 4.868e+00) | 4.364e+00 |
-3 | (2.089e+00, 8.090e+00) | 4.364e+00 |
1 | (2.089e+00, 3.757e+00) | 4.364e+00 |
2 | (2.089e+00, 3.357e+00) | 4.364e+00 |
3 | (2.089e+00, 4.147e+00) | 4.364e+00 |
4 | (2.089e+00, 6.798e+00) | 4.364e+00 |