Group at Tampere University of Technology:

Risto Silvennoinen, Ivan Argatov, Pauli Rautakorpi.

Publications:

*(You can ask for full text publications (in pdf format) from Risto Silvennoinen (risto.silvennoinen [at] tut.fi).*

I. Argatov, R. Silvennoinen

**Asymptotic modeling of unconstrained control of a tethered power kite moving along a given closed-loop spherical trajectory**

J Eng Math (2012) 72:187–203

**Abstract:**

Asymptotic modeling is developed for the fast crosswind motion of a power kite attached to a tether of constant length. It is assumed that the kite has a high lift-to-drag ratio. A mathematical model of kite dynamics including aerodynamic forces acting on the kite is taken from the literature. We assume that the kite is controlled directly via its velocity roll angle. The aerodynamic drag force experienced by the tether is taken into account, while the gravitational forces are neglected for simplicity’s sake. The kite dynamics is studied in the Frenet–Serret frame corresponding to a given trajectory. The regular problem of unconstrained control is solved asymptotically under the assumption that the inertia effect of the kite is negligible.

I. Argatov, P. Rautakorpi, R. Silvennoinen

**Apparent wind load effects on the tether of a kite power generator**

J. Wind Eng. Ind. Aerodyn. 99 (2011) 1079–1088

**Abstract:**

This paper is devoted to analytical modeling of apparent wind load effects on a tether constraining a power kite performing a fast crosswind motion. The reﬁned crosswind motion law generalized for accounting the kite control is derived in the case of equilibrium motion of the kite. The paper also presents the study of the effect of tether sag based on the mathematical model of a gently sloping tether line.

I. Argatov, R. Silvennoinen

**Energy conversion efﬁciency of the pumping kite wind generator**

Renewable Energy 35 (2010) 1052–1060

**Abstract:**

This paper is devoted to analytical modelling and numerical simulation of the so-called pumping kite wind generator whose operating principle is to mechanically drive a groundbased electric generator using tethered kites. On the basis of the reﬁned crosswind motion law, the mathematical model of steady crosswind motion of the tethered kite is constructed. Necessary conditions for optimality of the mean mechanical power functional are derived. Optimal control of the tether length rate is studied for the cases of open-loop and closed-loop ﬁgure-of-eight trajectories. The performance coefﬁcient of the pumping kite wind generator is introduced. Simple formulas for the mechanical power output are obtained.

I. Argatov, R. Silvennoinen

**Structural optimization of the pumping kite wind generator**

Struct Multidisc Optim (2010) 40:585–595

**Abstract:**

This paper focuses on structural optimization of the so-called pumping kite wind generator whose operating principle consists in mechanically driving a ground-based electric generator by means of tethered kites. The employed mathematical model of the kite wind generator is based on the reﬁned crosswind motion law derived under the assumption of equilibrium motion of the kite. The resulting simple approximate analytical formula for the mean mechanical power generated by the deploying kite is used for the constrained structural optimization of the pumping kite wind generator maximizing its electrical power output by adjusting the key structural parameters of the kite wind generator.

I. Argatov, P. Rautakorpi, R. Silvennoinen

**Estimation of the mechanical energy output of the kite wind generator**

Renewable Energy 34 (2009) 1525–1532

**Abstract:**

This paper is devoted to analytical modelling of so-called pumping kite generator whose operating principle is to mechanically drive a groundbased electric generator using tethered kites. The reﬁned crosswind motion law is derived in the case of equilibrium motion of the kite. The paper also presents the theory of a gently sloping kiteline. The main purpose of the study was to estimate the mechanical energy output of the pumping kite wind generator. A simple approximate formula for the mean mechanical power generated by the deploying kite is obtained.

P.Rautakorpi

**Leijavoimalan tehon arviointi** (Kandidaatintyö)

2008 Tampereen teknillinen yliopisto

Read here (in Finnish)